Transcriptomics Provide Insights into the Photoperiodic Regulation of Reproductive Diapause in the Green Lacewing, Chrysoperla nipponensis (Okamoto) (Neuroptera: Chrysopidae)

Chrysoperla nipponensis (Okamoto) displays typical adult reproductive diapause under short photoperiods; however, our understanding of the molecular mechanism underlying photoperiod-sensitive reproduction remains limited. In this study, we performed transcriptome profiling of four treatments (the diapause-sensitive stage and pre-diapause phase under long and short photoperiods) of C. nipponensis using RNA sequencing (RNA-seq). A total of 71,654 unigenes were obtained from the samples. Enrichment analysis showed that fatty acid metabolism-related pathways were altered under a short photoperiod. Moreover, β-oxidation-related gene expression was active during the diapause-sensitive period under a short photoperiod. The knockdown of juvenile hormone acid methyltransferase 1 (Jhamt1) prolonged the pre-oviposition period but did not affect the reproductive ability of female individuals in C. nipponensis. These findings provided us with a more comprehensive understanding of the molecular mechanisms of photoperiod-sensitive diapause and show that groundwork is crucial for bolstering the long-term storage and biocontrol potential of C. nipponensis.

The transcription factors and pathways underpinning male reproductive development in Arabidopsis

As Arabidopsis flowers mature, specialized cells within the anthers undergo meiosis, leading to the production of haploid microspores that differentiate into mature pollen grains, each containing two sperm cells for double fertilization. During pollination, the pollen grains are dispersed from the anthers to the stigma for subsequent fertilization. Transcriptomic studies have identified a large number of genes expressed over the course of male reproductive development and subsequent functional characterization of some have revealed their involvement in floral meristem establishment, floral organ growth, sporogenesis, meiosis, microsporogenesis, and pollen maturation. These genes encode a plethora of proteins, ranging from transcriptional regulators to enzymes. This review will focus on the regulatory networks that control male reproductive development, starting from flower development and ending with anther dehiscence, with a focus on transcription factors and some of their notable target genes.

Reproductive development of dairy heifers in an integrated livestock-forest system during the summer

This study aimed to assess the cortisol, body and reproductive development of prepubertal Holstein and Holstein-Gir ¾ heifers at 27 months of age maintained in an integrated livestock-forest (ILF) system for 60 summer days compared to the monoculture system in full sun (FS). The ILF system promoted changes (P=0.02) in the cortisol levels of Holstein-Gir ¾ heifers and did not affect weight gain in any of the breed groups studied. Animals in ILF system presented a lower (P=0.006) vulvar development for the rima height parameter and similar for the vulva width parameter. The ovarian follicular population of Holstein-Gir ¾ heifers in the ILF system was lower (P=0.004); however, for the Holstein heifers, no statistical difference was found, and numbers were higher (P=0.08) in the ILF system. None of the other ovarian parameters studied had any changes, and we also found important racial differences. Weight gain (P=0.003), vulvar development (P<0.001), and mean follicular size (P=0.008) were higher in the Holstein-Gir ¾ animals. Based on such results, the effect of the ILF system at 27 months of age on stress and reproductive parameters in the Holstein breed is considered positive, although negative effects have been detected on reproductive parameters in the Holstein-Gir ¾ breed.

Maternal Intake of Vitamin D Supplements during Pregnancy and Pubertal Timing in Children: A Population-Based Follow-Up Study

Maternal vitamin D may be important for several organ systems in the offspring, including the reproductive system. In this population-based follow-up study of 12,991 Danish boys and girls born 2000-2003, we investigated if maternal intake of vitamin D supplements during pregnancy was associated with pubertal timing in boys and girls. Information on maternal intake of vitamin D supplements was obtained by self-report in mid-pregnancy. Self-reported information on the current status of various pubertal milestones was obtained every six months throughout puberty. Mean differences in months at attaining each pubertal milestone and an average estimate for the mean difference in attaining all pubertal milestones were estimated according to maternal intake of vitamin D supplements using multivariable interval-censored regression models. Lower maternal intake of vitamin D supplements was associated with later pubertal timing in boys. For the average estimate, boys had 0.5 months (95% CI 0.1; 0.9) later pubertal timing per 5 µg/day lower maternal vitamin D supplement intake. Maternal intake of vitamin D supplements was not associated with pubertal timing in girls. Spline plots and sensitivity analyses supported the findings. Whether the observed association with boys' pubertal timing translates into an increased risk of disease in adulthood is unknown.

Maternal intake of folate and folic acid during pregnancy and pubertal timing in girls and boys: A population-based cohort study

BACKGROUND

Folate is essential for normal foetal development as it plays an important role for gene expression during different periods of foetal development. Thus, prenatal exposure to folate may have a programming effect on pubertal timing.

OBJECTIVES

To study the association between maternal intake of folate during pregnancy and pubertal timing in girls and boys.

METHODS

We studied 6585 girls and 6326 boys from a Danish population-based Puberty Cohort, 2000-2021. Information on maternal intake of folate from diet and folic acid from supplements was obtained from a food-frequency questionnaire in mid-pregnancy, and total folate was calculated as dietary folate equivalents. Information on age at menarche in girls, age at first ejaculation and voice break in boys, and Tanner stages, acne and axillary hair in both girls and boys was obtained every 6 months throughout puberty. We estimated mean monthly differences according to exposure groups for each pubertal milestone in addition to a combined estimate for the average age at attaining all pubertal milestones using multivariable interval-censored regression models. Total folate was analysed in quintiles, continuous and as restricted cubic splines.

RESULTS

Maternal intake of total folate in mid-pregnancy was not associated with pubertal timing in girls (combined estimate for overall pubertal timing per standard deviation (SD 325 μg/day) decrease in maternal intake of total folate: -0.14 months (95% confidence interval [CI] -0.51, 0.22)). Boys had slightly later overall pubertal timing per standard deviation (SD 325 μg/day) decrease in maternal intake of total folate (combined estimate: 0.40 months, 95% CI 0.01, 0.72). Spline plots supported these findings.

CONCLUSIONS

Prenatal exposure to low maternal intake of total folate in mid-pregnancy was not associated with pubertal timing in girls but associated with slightly later pubertal timing in boys. This minor delay is likely not of clinical importance.

CdTe-QDs Affect Reproductive Development of Plants through Oxidative Stress

With the continuous development of industry, an increasing number of nanomaterials are widely used. CdTe-QDs is a nanomaterial with good optical properties, but its release into the natural environment may pose a potential threat. The toxicity of nanoparticles in plants is beginning to be questioned, and the effect on phytotoxicity is unclear. In this study, we simulated air pollution and soil pollution (CdTe-QDs concentrations of 0, 0.2, 0.4, 0.8 mmol/L) by spraying and watering the seedlings, respectively. We determined the transport pathways of CdTe-QDs in Arabidopsis thaliana and their effects on plant reproductive growth. Spraying CdTe-QDs concentration >0.4 mmol/L significantly inhibited the formation of fruit and decreased the number of seeds. Observation with a laser confocal scanning microscope revealed that CdTe-QDs were mainly transported in plants through the vascular bundle, and spraying increased their accumulation in the anthers and ovaries. The expression level of genes associated with Cd stress was analyzed through RT-qPCR. CdTe-QDs significantly increased the expression levels of 10 oxidative stress-related genes and significantly decreased the expression levels of four cell-proliferation-related genes. Our results reveal for the first time the transport of CdTe-QDs in Arabidopsis flowers and demonstrate that QDs can cause abnormal pollen morphology, form defects of pollen vitality, and inhibit pollen tube growth in Arabidopsis through oxidative damage. These phenomena ultimately lead to the inability of Arabidopsis to complete the normal fertilization process and affect the reproductive growth of the plant.

Genetic evidence that brassinosteroids suppress pistils in the maize tassel independent of the jasmonic acid pathway

The developmental genetics of reproductive structure control in maize must consider both the staminate florets of the tassel and the pistillate florets of the ear synflorescences. Pistil abortion takes place in the tassel florets, and stamen arrest is affected in ear florets to give rise to the monoecious nature of maize. Gibberellin (GA) deficiency results in increased tillering, a dwarfed plant syndrome, and the retention of anthers in the ear florets of maize. The silkless1 mutant results in suppression of silks in the ear. We demonstrate in this study that jasmonic acid (JA) and GA act independently and show additive phenotypes resulting in androecious dwarf1;silkless1 double mutant plants. The persistence of pistils in the tassel can be induced by multiple mechanisms, including JA deficiency, GA excess, genetic control of floral determinacy, and organ identity. The silkless1 mutant can suppress both silks in the ear and the silks in the tassel of JA-deficient and AP2 transcription factor tasselseed mutants. We previously demonstrated that GA production was required for brassinosteroid (BR) deficiency to affect persistence of pistils in the tassel. We find that BR deficiency affects pistil persistence by an independent mechanism from the silkless1 mutant and JA pathway. The silkless1 mutant did not prevent the formation of pistils in the tassel by nana plant2 in double mutants. In addition, we demonstrate that there is more to the silkless1 mutant than just a suppression of pistil growth. We document novel phenotypes of silkless1 mutants including weakly penetrant ear fasciation and anther persistence in the ear florets. Thus, the JA/AP2 mechanism of pistil retention in the tassel and silk growth in the ear are similarly sensitive to loss of the SILKLESS1 protein, while the BR/GA mechanism is not.

Early Life Anti-Müllerian Hormone Trajectories in Infant Girls

BACKGROUND

Minipuberty is a period of increased reproductive axis activity in infancy, but the importance of this period is not well understood, especially in girls. Previous studies reported a peak in hormone concentrations at 3 to 4 months old. Our objective is to describe anti-Müllerian hormone (AMH) trajectories in the context of other minipuberty factors among healthy infant girls using longitudinal measures of AMH.

METHODS

The Infant Feeding and Early Development study is a longitudinal cohort study of healthy infants, recruited from hospitals in the Philadelphia area during 2010 to 2013. We measured AMH in 153 girls who contributed 1366 serum samples across 11 study visits over 36 weeks. We also measured follicle stimulating hormone (FSH), estradiol, and ovarian characteristics. We used latent class mixed effects models to cluster trajectories of AMH concentration with age. Using linear mixed models, we estimated FSH and ovarian characteristic trajectories separately by AMH cluster.

RESULTS

We classified infants into four clusters that represent patterns of AMH that were high and decreasing (decreasing), had a peak around 12 weeks or 20 weeks (early peak and middle peak), or were consistently low (low). Infants in these clusters differed in their FSH trajectories, timing of estradiol production, and ovarian characteristics.

CONCLUSIONS

The AMH clusters identified suggest variation in the timing and the magnitude of the minipuberty response in infant girls. The decreasing and low clusters have not been described previously and should be further evaluated to determine whether they represent an opportunity for the early identification of later reproductive conditions.

Mutant Tof11 alleles are highly accumulated in early planting-adaptable Japanese summer type soybeans

To avoid crop failure because of climate change, soybean (Glycine max (L.) Merrill) cultivars adaptable to early planting are required in western Japan. Because current Japanese cultivars may not be adaptable, genetic resources with high early-planting adaptability, and their genetic information must be developed. In the present study, summer type (ST) soybeans developed for early planting were used as plant materials. We examined their phenological characteristics and short reproductive period as an indicator of early planting adaptability and performed genetic studies. Biparental quantitative trait loci (QTL) analysis of a representative ST cultivar revealed a principal QTL for the reproductive period duration on chromosome 11. The results of resequencing analysis suggested that circadian clock-related Tof11 (soybean orthologue of PRR3) is a candidate QTL. Additionally, all 25 early planting-adaptable germplasms evaluated in this study possessed mutant alleles in Tof11, whereas 15 conventional cultivars only had wild-type alleles. These results suggest that mutant alleles in Tof11 are important genetic factors in the high adaptability to early planting of these soybeans, and thus, these alleles were acquired and accumulated in the ST soybean population.

Reproductive toxicity of maternal exposure to di(2-ethylhexyl)phthalate and butyl paraben (alone or in association) on both male and female Wistar offspring

Parabens and phthalates are commonly found as contaminants in human fluids and are able to provoke reproductive toxicity, being considered endocrine disruptors. To evaluate the effects of phthalate and paraben, alone or in combination, on reproductive development of the offspring, female pregnant Wistar rats were allocated in six experimental groups: Three control groups (gavage [CG], subcutaneous [CS], and gavage + subcutaneous) received corn oil as vehicle, and the remaining groups were exposed to di(2-ethylhexyl)phthalate (DEHP) (500 mg/kg, gavage), butyl paraben (BP) (100 mg/kg, subcutaneously), or MIX (DEHP + BP), from Gestational Day 12 until Postnatal Day (PND) 21. The following parameters were assessed on the offspring: anogenital distance and weight at PND 1, nipple counting at PND 13, puberty onset, estrous cycle, weights of reproductive and detoxifying organs, histological evaluation of reproductive organs, and sperm evaluations (counts, morphology, and motility). Female pups from MIX group presented reduced body weight at PND 1, lower AGD, and decreased endometrium thickness. Male animals showed decreased body weight at PND 1 and lower number of Sertoli cells on DEHP and MIX groups, MIX group revealed increase of abnormal seminiferous tubules, DEHP animals presented delayed preputial separation and higher percentage of immotile sperms, and BP males presented diminished number of Leydig cells. In conclusion, the male offspring was more susceptible to DEHP toxicity; even when mixed to paraben, the main negative effects observed seem to be due to antiandrogenic phthalate action. On the other hand, DEHP seems to be necessary to improve the effects of BP on reducing estrogen-dependent and increasing androgen-dependent events.

Cold-Induced RNA-Binding Protein and RNA-Binding Motif Protein 3: Two RNA Molecular Chaperones Closely Related to Reproductive Development and Reproductive System Diseases

Cold-induced RNA-binding protein (CIRP) and RNA-binding motif protein 3 (RBM3) have recently been reported to be involved in cold stress in mammals. These proteins are expressed at low levels in various normal cells, tissues, and organs but can be upregulated upon stimulation by multiple stressors. Studies have shown that CIRP and RBM3 are multifunctional RNA molecular chaperones with different biological functions in various physiological and pathophysiological processes, such as reproductive development, the inflammatory response, the immune response, nerve injury regulation, and tumorigenesis. This paper reviews recent studies on the structure, localization and correlation of CIRP and RBM3 with reproductive development and reproductive system diseases.

Evolutionary Relationships and Divergence of Filamin Gene Family Involved in Development and Stress in Cotton (Gossypium hirsutum L.)

Filamin protein is characterized by an N-terminal actin-binding domain that is followed by 24 Ig (immunoglobulin)-like repeats, which act as hubs for interactions with a variety of proteins. In humans, this family has been found to be involved in cancer cell invasion and metastasis and can be involved in a variety of growth signal transduction processes, but it is less studied in plants. Therefore, in this study, 54 Filamin gene family members from 23 plant species were investigated and divided into two subfamilies: FLMN and GEX2. Subcellular localization showed that most of the Filamin gene family members were located in the cell membrane. A total of 47 Filamin gene pairs were identified, most of which were whole-genome copies. Through the analyses of cis-acting elements, expression patterns and quantitative fluorescence, it was found that GH_ A02G0519 and GH_ D02G0539 are mainly expressed in the reproductive organs of upland cotton, and their interacting proteins are also related to the fertilization process, whereas GH_A02G0216 and GH_D02G0235 were related to stress. Thus, it is speculated that two genes of the GEX2 subfamily (GH_A02G0519 and GH_D02G0539) may be involved in the reproductive development of cotton and may affect the fertilization process of cotton. This study provides a theoretical basis for the further study of the cotton Filamin gene family.

Cone-setting in spruce is regulated by conserved elements of the age-dependent flowering pathway

Reproductive phase change is well characterized in angiosperm model species, but less studied in gymnosperms. We utilize the early cone-setting acrocona mutant to study reproductive phase change in the conifer Picea abies (Norway spruce), a gymnosperm. The acrocona mutant frequently initiates cone-like structures, called transition shoots, in positions where wild-type P. abies always produces vegetative shoots. We collect acrocona and wild-type samples, and RNA-sequence their messenger RNA (mRNA) and microRNA (miRNA) fractions. We establish gene expression patterns and then use allele-specific transcript assembly to identify mutations in acrocona. We genotype a segregating population of inbred acrocona trees. A member of the SQUAMOSA BINDING PROTEIN-LIKE (SPL) gene family, PaSPL1, is active in reproductive meristems, whereas two putative negative regulators of PaSPL1, miRNA156 and the conifer specific miRNA529, are upregulated in vegetative and transition shoot meristems. We identify a mutation in a putative miRNA156/529 binding site of the acrocona PaSPL1 allele and show that the mutation renders the acrocona allele tolerant to these miRNAs. We show co-segregation between the early cone-setting phenotype and trees homozygous for the acrocona mutation. In conclusion, we demonstrate evolutionary conservation of the age-dependent flowering pathway and involvement of this pathway in regulating reproductive phase change in the conifer P. abies.

Recycling amino acids ensures meiosis and seed development

Nitrogen (N) nutrition and meiosis demand large amounts of energy and widely affect crop yield. Recently, Yang and colleagues connected both processes by demonstrating that meiosis initiation depends on the electron-transfer flavoprotein/electron-transfer flavoprotein:ubiquinone oxidoreductase (ETF/ETFQO) system, whereas meiotic defects of the etfβ mutant can be rescued using N supplementation.

Quantifying the reproductive progression of sunflower using FIJI (Image J)

Sunflower (Helianthus annuus L.) is today the third leading oilseed crop in the world and seed yield is a valuable trait for breeders and researchers. The sunflower capitulum is composed of 700 to 3000 individual flowers on a flattered receptacle. Most reproductive stages (R5 to R6) have at least two disc flower phenophase's coexisting in the same receptacle (E1 to E4). Today, researchers in agroecology and breeders manually quantify the number of disc flowers that achieve the anthesis at different developmental stages of the receptacle. The presented method applies a bioinformatic tool to estimate: (1) the number of disc flowers of each phenophase that are constituting the sunflower´s capitula at different reproductive stages and, (2) the number of developing seeds of each sunflower capitulum. The ImageJ software was used as an image-analysis tool on sunflower capitula photographs. A use case and method validation for each presented protocol is provided. This method will contribute to correlation analysis in agroecological studies and also would be useful for the early prediction of seed yield in breeding programs.•This is a simple method for the estimation of the number of disc flowers at each phenophase in the sunflower receptacle.•It is based on integrating the knowledge of sunflower reproductive development with an open-source image analysis platform applied in single workflows.•This is a precise, non-destructive, rapid, and low-cost method; thus, it has the potential to be adopted as a phenotyping tool for sunflower breeding and research in agroecology.

Herbivory Amplifies Adverse Effects of Drought on Seedling Recruitment in a Keystone Species of Western North American Rangelands

Biotic interactions can affect a plant's ability to withstand drought. Such an effect may impact the restoration of the imperiled western North American sagebrush steppe, where seedlings are exposed to summer drought. This study investigated the impact of herbivory on seedlings' drought tolerance for a keystone species in this steppe, the shrub Artemisia tridentata. Herbivory effects were investigated in two field experiments where seedlings were without tree protectors or within plastic or metal-mesh tree protectors. Treatment effects were statistically evaluated on herbivory, survival, leaf water potential, and inflorescence development. Herbivory occurrence was 80% higher in seedlings without protectors. This damage occurred in early spring and was likely caused by ground squirrels. Most plants recovered, but herbivory was associated with higher mortality during the summer when seedlings experienced water potentials between -2.5 and -7 MPa. However, there were no differences in water potential between treatments, suggesting that the browsed plants were less tolerant of the low water potentials experienced. Twenty months after outplanting, the survival of plants without protectors was 40 to 60% lower than those with protectors. The percentage of live plants developing inflorescences was approximately threefold higher in plants with protectors. Overall, spring herbivory amplified susceptibility to drought and delayed reproductive development.

MS1/MMD1 homologues in the moss Physcomitrium patens are required for male and female gametogenesis

The Arabidopsis Plant HomeoDomain (PHD) proteins AtMS1 and AtMMD1 provide chromatin-mediated transcriptional regulation essential for tapetum-dependent pollen formation. This pollen-based male gametogenesis is a derived trait of seed plants. Male gametogenesis in the common ancestors of land plants is instead likely to have been reminiscent of that in extant bryophytes where flagellated sperms are produced by an elaborate gametophyte generation. Still, also bryophytes possess MS1/MMD1-related PHD proteins. We addressed the function of two MS1/MMD1-homologues in the bryophyte model moss Physcomitrium patens by the generation and analysis of reporter and loss-of-function lines. The two genes are together essential for both male and female fertility by providing functions in the gamete-producing inner cells of antheridia and archegonia. They are furthermore expressed in the diploid sporophyte generation suggesting a function during sporogenesis, a process proposed related by descent to pollen formation in angiosperms. We propose that the moss MS1/MMD1-related regulatory network required for completion of male and female gametogenesis, and possibly for sporogenesis, represent a heritage from ancestral land plants.

Functions and prospects of melatonin in plant growth, yield, and quality

Melatonin (N-acetyl-5-methoxytryptamine) is an indole molecule widely found in animals and plants. It is well known that melatonin improves plant resistance to various biotic and abiotic stresses due to its potent free radical scavenging ability while being able to modulate plant signaling and response pathways through mostly unknown mechanisms. In recent years, an increasing number of studies have shown that melatonin plays a crucial role in improving crop quality and yield by participating in the regulation of various aspects of plant growth and development. Here, we review the effects of melatonin on plant vegetative growth and reproductive development, and systematically summarize its molecular regulatory network. Moreover, the effective concentrations of exogenously applied melatonin in different crops or at different growth stages of the same crop are analysed. In addition, we compare endogenous phytomelatonin concentrations in various crops and different organs, and evaluate a potential function of phytomelatonin in plant circadian rhythms. The prospects of different approaches in regulating crop yield and quality through exogenous application of appropriate concentrations of melatonin, endogenous modification of phytomelatonin metabolism-related genes, and the use of nanomaterials and other technologies to improve melatonin utilization efficiency are also discussed.

Morpho-histology, endogenous hormone dynamics, and transcriptome profiling in Dacrydium pectinatum during female cone development

Dacrydium pectinatum de Laubenfels is a perennial dioeciously gymnosperm species dominant in tropical montane rain forests. Due to deforestation, natural disasters, long infancy, and poor natural regeneration ability, the population of this species has been significantly reduced and listed as an endangered protected plant. To better understand the female cone development in D. pectinatum, we examined the morphological and anatomical changes, analyzed the endogenous hormone dynamics, and profiled gene expression. The female reproductive structures were first observed in January. The morpho-histological observations suggest that the development of the D. pectinatum megaspore can be largely divided into six stages: early flower bud differentiation, bract primordium differentiation, ovule primordium differentiation, dormancy, ovule maturity, and seed maturity. The levels of gibberellins (GA), auxin (IAA), abscisic acid (ABA), and cytokinin (CTK) fluctuate during the process of female cone development. The female cones of D. pectinatum need to maintain a low level of GA3-IAA-ABA steady state to promote seed germination. The first transcriptome database for female D. pectinatum was generated, revealing 310,621 unigenes. Differential expression analyses revealed several floral (MADS2, AGL62, and LFY) and hormone biosynthesis and signal transduction (CKX, KO, KAO, ABA4, ACO, etc.) genes that could be critical for female cone development. Our study provides new insights into the cone development in D. pectinatum and the foundation for female cone induction with hormones.

The Rise and Fall of Billionaire siRNAs during Reproductive Development in Rice

RNA polymerase IV-dependent siRNAs, usually 24 nt in length, function in the RNA-directed DNA methylation that is responsible for de novo methylation in plants. We analyzed 24 nt siRNAs in inflorescences and found that among the 20,200 24 nt siRNA clusters, the top 0.81% highly expressed clusters accounted for more than 68% of the 24 nt siRNA reads in inflorescences. We named the highly expressed siRNAs as billionaire siRNAs (bill-siRNAs) and the less-expressed siRNAs as pauper siRNAs (pau-siRNAs). The bill-siRNAs in inflorescences are mainly derived from the ovary. Female gametes produced more bill-siRNAs than male gametes. In embryos and seedlings developed from fertilized egg cells, the bill-siRNAs from gametes disappeared. The endosperm, which develops from the fertilized central cell, also contained no bill-siRNAs from gametes but did contain newly and highly expressed siRNAs produced in different regions. In contrast, bill-siRNAs from the ovaries were maintained in the seed coat. The biosynthesis of bill-siRNAs in various tissues and cells is dependent on OsRDR2 (RNA-dependent RNA polymerase 2) and Pol IV (DNA-dependent RNA polymerase IV). Similar to the pau-siRNAs, the first base of bill-siRNAs is enriched at adenine, and bill-siRNAs can direct DNA methylation in various tissues.

Multiple Roles of SMC5/6 Complex during Plant Sexual Reproduction

Chromatin-based processes are essential for cellular functions. Structural maintenance of chromosomes (SMCs) are evolutionarily conserved molecular machines that organize chromosomes throughout the cell cycle, mediate chromosome compaction, promote DNA repair, or control sister chromatid attachment. The SMC5/6 complex is known for its pivotal role during the maintenance of genome stability. However, a dozen recent plant studies expanded the repertoire of SMC5/6 complex functions to the entire plant sexual reproductive phase. The SMC5/6 complex is essential in meiosis, where its activity must be precisely regulated to allow for normal meiocyte development. Initially, it is attenuated by the recombinase RAD51 to allow for efficient strand invasion by the meiosis-specific recombinase DMC1. At later stages, it is essential for the normal ratio of interfering and non-interfering crossovers, detoxifying aberrant joint molecules, preventing chromosome fragmentation, and ensuring normal chromosome/sister chromatid segregation. The latter meiotic defects lead to the production of diploid male gametes in Arabidopsis SMC5/6 complex mutants, increased seed abortion, and production of triploid offspring. The SMC5/6 complex is directly involved in controlling normal embryo and endosperm cell divisions, and pioneer studies show that the SMC5/6 complex is also important for seed development and normal plant growth in cereals.

Maternal Paracetamol Intake During Pregnancy-Impacts on Offspring Reproductive Development

Paracetamol (acetaminophen) is the preferred antipyretic/analgesic for pregnant women as it is believed there are no adverse fetal effects at the recommended dose. However, emerging evidence suggests that intrauterine paracetamol exposure may be associated with certain urogenital/reproductive disorders in the offspring. In this mini-review, we describe human fetal sex development and possible pharmacological mechanisms by which paracetamol may disrupt this process, including reduced testicular production of testosterone and/or insulin-like peptide 3. We then review the available epidemiological literature on associations between maternal paracetamol exposure and offspring sexual development. Three epidemiological studies have reported associations between maternal paracetamol intake and increased risk of cryptorchidism, although five others have not. None have found associations with hypospadias or penile length. Two out of three studies have reported a shorter anogenital distance (a marker of androgen action during the masculinisation programming window, ∼8-14 weeks of gestation) in male infants antenatally exposed to paracetamol. One study has described a dose-dependent relationship between maternal paracetamol consumption and earlier female (but not male) attainment of puberty. Such epidemiological analyses are complicated by various factors, including method of paracetamol exposure assessment (usually retrospective self-report), variation in diagnostic accuracy, selection bias, confounding by clinical indication, and demographic/genetic differences between geographically separated populations. There is an urgent need for stronger evidence in this area, from both relevant experimental studies and large, carefully-designed prospective studies. In the meantime, a precautionary attitude to gestational paracetamol usage should be considered as the evidence for clinically significant reproductive effects in humans is limited.

Molecular genetic insights into orchid reproductive development

Orchids are members of the Orchidaceae, one of the largest families of flowering plants, and occupy a wide range of ecological habitats with highly specialized reproductive features. They exhibit unique developmental characteristics, such as generation of storage organs during flowering and spectacular floral morphological features, which contribute to their reproductive success in different habitats in response to various environmental cues. Here we review current understanding of the molecular genetic basis of orchid reproductive development, including flowering time control, floral patterning and flower color, with a focus on the orchid genes that have been functionally validated in plants. Furthermore, we summarize recent progress in annotating orchid genomes, and discuss how integration of high-quality orchid genome sequences with other advanced tools, such as the ever-improving multi-omics approaches and genome editing technologies as well as orchid-specific technical platforms, could open up new avenues to elucidate the molecular genetic basis of highly specialized reproductive organs and strategies in orchids.

The Autophagy Genes ChATG4 and ChATG8 Are Required for Reproductive Development, Virulence, and Septin Assembly in Cochliobolus heterostrophus

Autophagy is a highly conserved degrading process that is crucial for cell growth and development in eukaryotes, especially when they face starvation and stressful conditions. To evaluate the functions of Atg4 and Atg8 in mycelial growth, asexual and sexual development, and virulence in Cochliobolus heterostrophus, ΔChatg4 and ΔChatg8 mutants were generated by gene replacement. Strains deleted for ChATG4 and ChATG8 genes showed significant changes in vegetative growth and development of conidia and ascospores compared with the wild-type strain. The autophagy process was blocked and virulence was reduced dramatically in ΔChatg4 and ΔChatg8 mutants. In addition, deletion of ChATG4 and ChATG8 disordered Cdc10 subcellular localization and formation of septin rings. The direct physical interaction between ChAtg4 and ChAtg8 was detected by yeast two-hybrid assay, and ChAtg4-GFP was dispersed throughout the cytoplasm, although GFP-ChAtg8 appeared as punctate structures. All phenotypes were restored in complemented strains. Taken together, these findings indicate that ChATG4 and ChATG8 are crucial for autophagy to regulate fungal growth, development, virulence, and localization of septin in C. heterostrophus.

Plant GDSL Esterases/Lipases: Evolutionary, Physiological and Molecular Functions in Plant Development

GDSL esterases/lipases (GELPs), present throughout all living organisms, have been a very attractive research subject in plant science due mainly to constantly emerging properties and functions in plant growth and development under both normal and stressful conditions. This review summarizes the advances in research on plant GELPs in several model plants and crops, including Arabidopsis, rice, maize and tomato, while focusing on the roles of GELPs in regulating plant development and plant-environment interactions. In addition, the possible regulatory network and mechanisms of GELPs have been discussed.

Receptor-like protein kinases in plant reproduction: Current understanding and future perspectives

Reproduction is a crucial process in the life span of flowering plants, and directly affects human basic requirements in agriculture, such as grain yield and quality. Typical receptor-like protein kinases (RLKs) are a large family of membrane proteins sensing extracellular signals to regulate plant growth, development, and stress responses. In Arabidopsis thaliana and other plant species, RLK-mediated signaling pathways play essential roles in regulating the reproductive process by sensing different ligand signals. Molecular understanding of the reproductive process is vital from the perspective of controlling male and female fertility. Here, we summarize the roles of RLKs during plant reproduction at the genetic and molecular levels, including RLK-mediated floral organ development, ovule and anther development, and embryogenesis. In addition, the possible molecular regulatory patterns of those RLKs with unrevealed mechanisms during reproductive development are discussed. We also point out the thought-provoking questions raised by the research on these plant RLKs during reproduction for future investigation.

Rice functional genomics: decades' efforts and roads ahead

Rice (Oryza sativa L.) is one of the most important crops in the world. Since the completion of rice reference genome sequences, tremendous progress has been achieved in understanding the molecular mechanisms on various rice traits and dissecting the underlying regulatory networks. In this review, we summarize the research progress of rice biology over past decades, including omics, genome-wide association study, phytohormone action, nutrient use, biotic and abiotic responses, photoperiodic flowering, and reproductive development (fertility and sterility). For the roads ahead, cutting-edge technologies such as new genomics methods, high-throughput phenotyping platforms, precise genome-editing tools, environmental microbiome optimization, and synthetic methods will further extend our understanding of unsolved molecular biology questions in rice, and facilitate integrations of the knowledge for agricultural applications.

Rice functional genomics: decades' efforts and roads ahead

Rice (Oryza sativa L.) is one of the most important crops in the world. Since the completion of rice reference genome sequences, tremendous progress has been achieved in understanding the molecular mechanisms on various rice traits and dissecting the underlying regulatory networks. In this review, we summarize the research progress of rice biology over past decades, including omics, genome-wide association study, phytohormone action, nutrient use, biotic and abiotic responses, photoperiodic flowering, and reproductive development (fertility and sterility). For the roads ahead, cutting-edge technologies such as new genomics methods, high-throughput phenotyping platforms, precise genome-editing tools, environmental microbiome optimization, and synthetic methods will further extend our understanding of unsolved molecular biology questions in rice, and facilitate integrations of the knowledge for agricultural applications.

Gonadal morphology and difference in reproductive development of two isolated populations of Astyanax rivularis (Teleostei, Characidae)

Individuals of the same species may present different reproductive tactics depending on the environment in which they develop and mature. The present study aimed to define the gonadal development phases of males and females of Astyanax rivularis and to carry out a comparative analysis of the reproductive development of specimens captured in two isolated environments of the São Francisco River basin in Serra da Canastra, Brazil (Point 1: low vegetation and river showing calm and crystalline waters with small well formations; Point 2: current waters, and well-established areas of arboreal vegetation). Thus, the gonads of A. rivularis specimens were collected, fixed and processed with techniques for light microscopy. Five maturation phases of the females' reproductive cycle were established: immature, developing, spawning capable, regressing and regenerating. Three maturation phases of the males' reproductive cycle were observed: spawning capable, regressing, and regenerating. There are differences in the phases of gonadal development of A. rivularis between the two sampling points so that, possibly, animals upstream of the waterfall demonstrate a delay in the reproductive cycle in relation to animals downstream.

A Non-Shedding Fruit Elaeis oleifera Palm Reveals Perturbations to Hormone Signaling, ROS Homeostasis, and Hemicellulose Metabolism

The developmentally programmed loss of a plant organ is called abscission. This process is characterized by the ultimate separation of adjacent cells in the abscission zone (AZ). The discovery of an American oil palm (Elaeis oleifera) variant that does not shed its has allowed for the study of the mechanisms of ripe fruit abscission in this species. A comparative transcriptome analysis was performed to compare the fruit AZs of the non-shedding E. oleifera variant to an individual of the same progeny that sheds its ripe fruit normally. The study provides evidence for widespread perturbation to gene expression in the AZ of the non-shedding variant, compared to the normal fruit-shedding control, and offers insight into abscission-related functions. Beyond the genes with known or suspected roles during organ abscission or indehiscence that were identified, a list of genes with hormone-related functions, including ethylene, jasmonic acid, abscisic acid, cytokinin and salicylic acid, in addition to reactive oxygen species (ROS) metabolism, transcriptional responses and signaling pathways, was compiled. The results also allowed a comparison between the ripe fruit abscission processes of the African and American oil palm species at the molecular level and revealed commonalities with environmental stress pathways.

Nucleolar histone deacetylases HDT1, HDT2 and HDT3 regulate plant reproductive development

Nucleolus is a membrane-less organelle where ribosomes are assembled and rRNAs transcribed and processed. The assembled ribosomes composed of ribosomal proteins and rRNAs synthesize proteins for cell survival. In plants, the loss of nucleolar ribosomal proteins often causes gametophytically or embryonically lethality. The amount of rRNAs are under stringent regulation according to demand and partially switched off by epigenetic modifications. However, the molecular mechanism for the selective activation or silencing is still unclear, and the transcriptional coordination of rRNAs and ribosomal proteins is also unknown. Here we report the critical role of three Arabidopsis nucleolar protein HDT1, HDT2 and HDT3 in fertility and transcription of rDNAs and rRNA processing-related genes through histone acetylation. This study highlights the important roles of transcriptional repression of ribosome biogenesis-related genes for plant reproductive development.

Population Dynamics and Reproductive Developmental Analysis of Helicoverpa armigera (Lepidoptera: Noctuidae) Trapped Using Food Attractants in the Field

Monitoring adult populations of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), a major agricultural pest, provides data useful for its control. Food attractants, considered as adult insect behavior regulators based on the preference of an herbivorous pest for food sources or their volatiles, also have great potential for monitoring populations. To study the feasibility of monitoring the population dynamics and reproductive development of H. armigera in the field using food attractants, we quantitatively analyzed reproductive organ development of adults in a laboratory population as a way to predict the reproductive development of adults trapped using food attractants in the field in 2019 and 2020. The adults trapped using food attractants had obvious generational changes and the same trends in variation for females and males. The extent of ovarian development in trapped females tended to increase within each generation, and the major axis length of testis in trapped males tended to decrease. Reproductive developmental status of trapped adults also differed significantly among months. This study shows that by trapping H. armigera with food attractants, the population dynamics of adults in the field can be monitored, and reproductive anatomy can also be used to monitor adult reproductive status. These approaches are a new way to forecast the population dynamics of this pest.

A tale of two morphs: developmental patterns and mechanisms of seed coat differentiation in the dimorphic diaspore model Aethionema arabicum (Brassicaceae)

The developmental transition from a fertilized ovule to a dispersed diaspore (seed or fruit) involves complex differentiation processes of the ovule's integuments leading to the diversity in mature seed coat structures in angiosperms. In this study, comparative imaging and transcriptome analysis were combined to investigate the morph-specific developmental differences during outer seed coat differentiation and mucilage production in Aethionema arabicum, the Brassicaceae model for diaspore dimorphism. One of the intriguing adaptations of this species is the production and dispersal of morphologically distinct, mucilaginous and non-mucilaginous diaspores from the same plant (dimorphism). The dehiscent fruit morph programme producing multiple mucilaginous seed diaspores was used as the default trait combination, similar to Arabidopsis thaliana, and was compared with the indehiscent fruit morph programme leading to non-mucilaginous diaspores. Synchrotron-based radiation X-ray tomographic microscopy revealed a co-ordinated framework of morph-specific early changes in internal anatomy of developing A. arabicum gynoecia including seed abortion in the indehiscent programme and mucilage production by the mucilaginous seed coat. The associated comparative analysis of the gene expression patterns revealed that the unique seed coat dimorphism of Ae. arabicum provides an excellent model system for comparative study of the control of epidermal cell differentiation and mucilage biosynthesis by the mucilage transcription factor cascade and their downstream cell wall and mucilage remodelling genes. Elucidating the underlying molecular framework of the dimorphic diaspore syndrome is key to understanding differential regulation of bet-hedging survival strategies in challenging environments, timely in the face of global climatic change.

Flower Development of Heterodichogamous Juglans mandshurica (Juglandaceae)

Juglans mandshurica is a monoecious heterodichogamous species with protogynous and protandrous mating strategies that occur at a 1:1 ratio and are randomly distributed in the population. The inconsistent male and female flowering periods of the same mating type result in an imbalance of the ratio of male and female flowers, contributing to the low yield of this species. However, little more is known about its floral development. Following three consecutive years of observations, histological analysis, and scanning electron microscopy, we found that the morphological and anatomical development of the male and female flowers were synchronous. The male floral morphological development of J. mandshurica was divided into seven phases, while that of the female flower was nine. Four stages were shared between the male and female flower's anatomical development. Our findings indicate that there was minimal overlap between sexual functions within the same mating type, guaranteeing synchronization, mutual non-interference, outcrossing, and avoidance of self-fertilization. These results provide a theoretical basis for the improvement of fruit yield and quality through the reasonable allocation of protogynous and protandrous individuals in a population, and for artificial pollination control. Further, these findings lay a foundation for further research on the genetic mechanisms and environmental effects on flower development of heterodichogamous J. mandshurica.

Evolution and Functional Divergence of SUN Genes in Plants

SUN-domain containing proteins are crucial nuclear membrane proteins involved in a plethora of biological functions, including meiosis, nuclear morphology, and embryonic development, but their evolutionary history and functional divergence are obscure. In all, 216 SUN proteins from protists, fungi, and plants were divided into two monophyletic clades (Cter-SUN and Mid-SUN). We performed comprehensive evolutionary analyses, investigating the characteristics of different subfamilies in plants. Mid-SUNs further evolved into two subgroups, SUN3 and SUN5, before the emergence of the ancestor of angiosperms, while Cter-SUNs retained one subfamily of SUN1. The two clades were distinct from each other in the conserved residues of the SUN domain, the TM motif, and exon/intron structures. The gene losses occurred with equal frequency between these two clades, but duplication events of Mid-SUNs were more frequent. In cotton, SUN3 proteins are primarily expressed in petals and stamens and are moderately expressed in other tissues, whereas SUN5 proteins are specifically expressed in mature pollen. Virus-induced knock-down and the CRISPR/Cas9-mediated knockout of GbSUN5 both showed higher ratios of aborted seeds, although pollen viability remained normal. Our results indicated divergence of biological function between SUN3 and SUN5, and that SUN5 plays an important role in reproductive development.

Studies of moss reproductive development indicate that auxin biosynthesis in apical stem cells may constitute an ancestral function for focal growth control

The plant hormone auxin is a key factor for regulation of plant development, and this function was probably reinforced during the evolution of early land plants. We have extended the available toolbox to allow detailed studies of how auxin biosynthesis and responses are regulated in moss reproductive organs, their stem cells and gametes to better elucidate the function of auxin in the morphogenesis of early land plants. We measured auxin metabolites and identified IPyA (indole-3-pyruvic acid) as the main biosynthesis pathway in Physcomitrium (Physcomitrella) patens and established knock-out, overexpressor and reporter lines for biosynthesis genes which were analyzed alongside previously reported auxin-sensing and transport reporters. Vegetative and reproductive apical stem cells synthesize auxin. Sustained stem cell activity depends on an inability to sense the auxin produced while progeny of the stem cells respond to the auxin, aiding in the control of cell division, expansion and differentiation. Gamete precursors are dependent on a certain degree of auxin sensing, while the final differentiation is a low auxin-sensing process. Tha data presented indicate that low auxin activity may represent a conserved hallmark of land plant gametes, and that local auxin biosynthesis in apical stem cells may be part of an ancestral mechanism to control focal growth.

Versatile Roles of Aquaporins in Plant Growth and Development

Aquaporins (AQPs) are universal membrane integrated water channel proteins that selectively and reversibly facilitate the movement of water, gases, metalloids, and other small neutral solutes across cellular membranes in living organisms. Compared with other organisms, plants have the largest number of AQP members with diverse characteristics, subcellular localizations and substrate permeabilities. AQPs play important roles in plant water relations, cell turgor pressure maintenance, the hydraulic regulation of roots and leaves, and in leaf transpiration, root water uptake, and plant responses to multiple biotic and abiotic stresses. They are also required for plant growth and development. In this review, we comprehensively summarize the expression and roles of diverse AQPs in the growth and development of various vegetative and reproductive organs in plants. The functions of AQPs in the intracellular translocation of hydrogen peroxide are also discussed.

Increased sperm production linked to competition in the maternal social environment

Maternal or early life effects may prepare offspring for similar social conditions to those experienced by their mothers. For males, the ability to achieve mating and fertilization success is a key social challenge. Competitive conditions may therefore favour increased body size or ejaculate production in male offspring. We tested this experimentally by comparing reproductive traits of adult male bank voles (Myodes glareolus), whose mothers had experienced contrasting encounter regimes with female conspecifics while breeding. We found that daily sperm production rates and epididymis mass were significantly higher when dams had experienced more frequent encounters with female conspecifics. This response to maternal and early life experience was specific to sperm production and storage, with no evidence for effects on male body mass or the size of testes and accessory reproductive glands. Our findings reveal a potentially adaptive effect of maternal and early life experience on the development of sperm production, which is worthy of wider investigation.

Activation tagging identifies Arabidopsis transcription factor AtMYB68 for heat and drought tolerance at yield determining reproductive stages

Heat stress occurring at reproductive stages can result in significant and permanent damage to crop yields. However, previous genetic studies in understanding heat stress response and signaling were performed mostly on seedling and plants at early vegetative stages. Here we identify, using a developmentally defined, gain-of-function genetic screen with approximately 18 000 Arabidopsis thaliana activation-tagged lines, a mutant that maintained productive seed set post-severe heat stress during flowering. Genome walking indicated this phenotype was caused by the insertion of 35S enhancers adjacent to a nuclear localized transcription factor AtMYB68. Subsequent overexpression analysis confirmed that AtMYB68 was responsible for the reproductive heat tolerance of the mutant. Furthermore, these transgenic Arabidopsis plants exhibited enhanced abscisic acid sensitivity at and post-germination, reduced transpirational water loss during a drought treatment, and enhanced seed yield under combined heat and drought stress during flowering. Ectopic expression of AtMYB68 in Brassica napus driven either by 35S or by heat-inducible promoter recapitulated the enhanced reproductive heat stress and drought tolerance phenotypes observed in the transgenic Arabidopsis. The improvement to heat stress is likely due to enhanced pollen viability observed in the transgenic plants. More importantly, the transgenic canola showed significant yield advantages over the non-transgenic controls in multiple locations, multiple season field trials under various drought and heat stress conditions. Together these results suggest that AtMYB68 regulate plant stress tolerance at the most important yield determining stage of plant development, and is an effective target for crop yield protection under current global climate volatility.

Feeling the heat: developmental and molecular responses of wheat and barley to high ambient temperatures

The increasing demand for global food security in the face of a warming climate is leading researchers to investigate the physiological and molecular responses of cereals to rising ambient temperatures. Wheat and barley are temperate cereals whose yields are adversely affected by high ambient temperatures, with each 1 °C increase above optimum temperatures reducing productivity by 5-6%. Reproductive development is vulnerable to high-temperature stress, which reduces yields by decreasing grain number and/or size and weight. In recent years, analysis of early inflorescence development and genetic pathways that control the vegetative to floral transition have elucidated molecular processes that respond to rising temperatures, including those involved in the vernalization- and photoperiod-dependent control of flowering. In comparison, our understanding of genes that underpin thermal responses during later developmental stages remains poor, thus highlighting a key area for future research. This review outlines the responses of developmental genes to warmer conditions and summarizes our knowledge of the reproductive traits of wheat and barley influenced by high temperatures. We explore ways in which recent advances in wheat and barley research capabilities could help identify genes that underpin responses to rising temperatures, and how improved knowledge of the genetic regulation of reproduction and plant architecture could be used to develop thermally resilient cultivars.

Regulation of ovule initiation by gibberellins and brassinosteroids in tomato and Arabidopsis: two plant species, two molecular mechanisms

Ovule primordia formation is a complex developmental process with a strong impact on the production of seeds. In Arabidopsis this process is controlled by a gene network, including components of the signalling pathways of auxin, brassinosteroids (BRs) and cytokinins. Recently, we have shown that gibberellins (GAs) also play an important role in ovule primordia initiation, inhibiting ovule formation in both Arabidopsis and tomato. Here we reveal that BRs also participate in the control of ovule initiation in tomato, by promoting an increase on ovule primordia formation. Moreover, molecular and genetic analyses of the co-regulation by GAs and BRs of the control of ovule initiation indicate that two different mechanisms occur in tomato and Arabidopsis. In tomato, GAs act downstream of BRs. BRs regulate ovule number through the downregulation of GA biosynthesis, which provokes stabilization of DELLA proteins that will finally promote ovule primordia initiation. In contrast, in Arabidopsis both GAs and BRs regulate ovule number independently of the activity levels of the other hormone. Taken together, our data strongly suggest that different molecular mechanisms could operate in different plant species to regulate identical developmental processes even, as for ovule primordia initiation, if the same set of hormones trigger similar responses, adding a new level of complexity.

Molecular genetic analyses of abiotic stress responses during plant reproductive development

Plant responses to abiotic stresses during vegetative growth have been extensively studied for many years. Daily environmental fluctuations can have dramatic effects on plant vegetative growth at multiple levels, resulting in molecular, cellular, physiological, and morphological changes. Plants are even more sensitive to environmental changes during reproductive stages. However, much less is known about how plants respond to abiotic stresses during reproduction. Fortunately, recent advances in this field have begun to provide clues about these important processes, which promise further understanding and a potential contribution to maximize crop yield under adverse environments. Here we summarize information from several plants, focusing on the possible mechanisms that plants use to cope with different types of abiotic stresses during reproductive development, and present a tentative molecular portrait of plant acclimation during reproductive stages. Additionally, we discuss strategies that plants use to balance between survival and productivity, with some comparison among different plants that have adapted to distinct environments.

Phenotyping the Chilling and Freezing Responses of Young Microspore Stage Wheat Spikes Using Targeted Metabolome and Lipidome Profiling

Chilling and frost conditions impose major yield restraints to wheat crops in Australia and other temperate climate regions. Unpredictability and variability of field frost events are major impediments for cold tolerance breeding. Metabolome and lipidome profiling were used to compare the cold response in spikes of cold-tolerant Young and sensitive variety Wyalkatchem at the young microspore (YM) stage of pollen development. We aimed to identify metabolite markers that can reliably distinguish cold-tolerant and sensitive wheat varieties for future cold-tolerance phenotyping applications. We scored changes in spike metabolites and lipids for both varieties during cold acclimation after initial and prolonged exposure to combined chilling and freezing cycles (1 and 4 days, respectively) using controlled environment conditions. The two contrasting wheat varieties showed qualitative and quantitative differences in primary metabolites involved in osmoprotection, but differences in lipid accumulation most distinctively separated the cold response of the two wheat lines. These results resemble what we previously observed in flag leaves of the same two wheat varieties. The fact that this response occurs in tissue types with very different functions indicates that chilling and freezing tolerance in these wheat lines is associated with re-modelling of membrane lipid composition to maintain membrane fluidity.

Complex Molecular Evolution and Expression of Expansin Gene Families in Three Basic Diploid Species of Brassica

Expansins are a kind of structural proteins of the plant cell wall, and they enlarge cells by loosening the cell walls. Therefore, expansins are involved in many growth and development processes. The complete genomic sequences of Brassica rapa, Brassica oleracea and Brassica nigra provide effective platforms for researchers to study expansin genes, and can be compared with analogues in Arabidopsis thaliana. This study identified and characterized expansin families in B. rapa, B. oleracea, and B. nigra. Through the comparative analysis of phylogeny, gene structure, and physicochemical properties, the expansin families were divided into four subfamilies, and then their expansion patterns and evolution details were explored accordingly. Results showed that after the three species underwent independent evolution following their separation from A. thaliana, the expansin families in the three species had increased similarities but fewer divergences. By searching divergences of promoters and coding sequences, significant positive correlations were revealed among orthologs in A. thaliana and the three basic species. Subsequently, differential expressions indicated extensive functional divergences in the expansin families of the three species, especially in reproductive development. Hence, these results support the molecular evolution of basic Brassica species, potential functions of these genes, and genetic improvement of related crops.

Mini-hysteroscopy for a married virgin with a tubular ectocervical giant polyp combined with psychosexual dysfunction: a case report

A 32-year-old virgin presented with psychosexual dysfunction and a mass in the vulva. The mass arose from the cervix with a thin pedicle and it was 6 × 1.5 cm. The mass protruded outside of the hymen, it had a canal inside and an opening at the distal end, and it had a genital-like appearance. A mucosal fold was found in the tubular lumen. Fibrous smooth muscle was observed in the tubal wall, which was covered by squamous and endometrial glandular epithelium on each side. A cervical giant polyp with a canal inside the polyp might be differentially diagnosed from prolapsed genitals and abnormal sexual development. Polypectomy by mini-hysteroscopy was effective for alleviating psychosexual dysfunction caused by the mass in this patient.

Influence of hyperproteinemia on reproductive development in an invertebrate model

Hyperproteinemia is a severe metabolic disease characterized by abnormally elevated plasma protein concentrations (PPC). However, there is currently no reliable animal model for PPC, and the pathological mechanism of hyperproteinemia thus remains unclear. In this study, we evaluated the effects of hyperproteinemia on reproductive development in an invertebrate silkworm model with a controllable PPC and no primary disease effects. High PPC inhibited the synthesis of vitellogenin and 30K protein essential for female ovarian development in the fat body of metabolic tissues, and inhibited their transport through the hemolymph to the ovary. High PPC also induced programmed cell death in testis and ovary cells, slowed the development of germ cells, and significantly reduced the reproductive coefficient. Furthermore, the intensities and mechanisms of high-PPC-induced reproductive toxicity differed between sexes in this silkworm model.

Calorie Restriction Modulates Reproductive Development and Energy Balance in Pre-Pubertal Male Rats

The objective was to determine effects of feed restriction and refeeding on reproductive development and energy balance in pre-pubertal male rats. Sprague Dawley rats (n = 32, 24 days old, ~65 g), were randomly allocated into four treatments (n = 8/treatment): (1) Control (CON, ad libitum feed; (2) Mild Restriction (MR, rats fed 75% of CON consumption); (3) Profound Restriction (PR, 50% of CON consumption); or (4) Refeeding (RF, 50% restriction for 14 days, and then ad libitum for 7 days). Feed restriction delayed reproductive development and decreased energy balance and tissue accretion, with degree of reproductive and metabolic dysfunctions related to restriction severity. In RF rats, refeeding largely restored testis weight, sperm production (per gram and total), plasma IGF-1, leptin and insulin concentrations and energy expenditure, although body composition did not completely recover. On Day 50, more CON and RF rats than PR rats were pubertal (5/6, 4/5 and 1/6, respectively; plasma testosterone >1 ng/mL) with the MR group (4/6) not different. Our hypothesis was supported: nutrient restriction of pre-pubertal rats delayed reproductive development, induced negative energy balance and decreased metabolic hormone concentrations (commensurate with restriction), whereas short-term refeeding after profound restriction largely restored reproductive end points and plasma hormone concentrations, but not body composition.

Heat Stress in Legume Seed Setting: Effects, Causes, and Future Prospects

Grain legumes provide a rich resource of plant nutrition to human diets and are vital for food security and sustainable cropping. Heat stress during flowering has a detrimental effect on legume seed yield, mainly due to irreversible loss of seed number. To start with, we provide an overview of the developmental and physiological basis of controlling seed setting in response to heat stress. It is shown that every single process of seed setting including male and female gametophyte development, fertilization, and early seed/fruit development is sensitive to heat stress, in particular male reproductive development in legume crops is especially susceptible. A series of physiochemical processes including heat shock proteins, antioxidants, metabolites, and hormones centered with sugar starvation are proposed to play a key role in regulating legume seed setting in response to heat stress. The exploration of the molecular mechanisms underlying reproductive heat tolerance is in its infancy. Medicago truncatula, with a small diploid genome, and well-established transformation system and molecular platforms, has become a valuable model for testing gene function that can be applied to advance the physiological and molecular understanding of legume reproductive heat tolerance.

Heterochronic reproductive developmental processes between diploid and tetraploid cytotypes of Paspalum rufum

BACKGROUND AND AIMS

Apomixis is an asexual reproductive mode via seeds that generate maternal clonal progenies. Although apomixis in grasses is mainly expressed at the polyploid level, some natural diploid genotypes of Paspalum rufum produce aposporous embryo sacs in relatively high proportions and are even able to complete apomixis under specific conditions. However, despite the potential for apomixis, sexuality prevails in diploids, and apomixis expression is repressed for an as yet undetermind reason. Apomixis is thought to derive from a deregulation of one or a few components of the sexual pathway that could be triggered by polyploidy and/or hybridization. The objectives of this work were to characterize and compare the reproductive development and the timing of apospory initial (AI) emergence between diploid genotypes with potential for apomixis and facultative apomictic tetraploid cytotypes of P. rufum.

METHODS

Reproductive characterization was performed by cytoembryological observations of cleared ovaries and anthers during all reproductive development steps and by quantitative evaluation of the ovule growth parameters.

KEY RESULTS

Cytoembryological observations showed that in diploids, both female and male reproductive development is equally synchronized, but in tetraploids, megasporogenesis and early megagametogenesis are delayed with respect to microsporogenesis and early microgametogenesis. This delay was also seen when ovary growth was taken as a reference parameter. The analysis of the onset of AIs revealed that they emerge during different developmental periods depending on the ploidy level. In diploids, the AIs appeared along with the tetrad (or triad) of female meiocytes, but in tetraploids they appeared earlier, at the time of the megaspore mother cell. In both cytotypes, AIs can be seen even during megagametogenesis.

CONCLUSIONS

Overall observations reveal that female sexual reproductive development is delayed in tetraploids as compared with diploid genotypes, mainly at meiosis. In tetraploids, AIs appear at earlier sexual developmental stages than in diploids, and they accumulate up to the end of megasporogenesis. The longer extension of megasporogenesis in tetraploids could favour AI emergence and also apomixis success.