LsMybW-encoding R2R3-MYB transcription factor is responsible for a shift from black to white in lettuce seed

KEY MESSAGE

We identified LsMybW as the allele responsible for the shift in color from black to white seeds in wild ancestors of lettuce to modern cultivars. Successfully selected white seeds are a key agronomic trait for lettuce cultivation and breeding; however, the mechanism underlying the shift from black-in its wild ancestor-to white seeds remains uncertain. We aimed to identify the gene/s responsible for white seed trait in lettuce. White seeds accumulated less proanthocyanidins than black seeds, similar to the phenotype observed in Arabidopsis TT2 mutants. Genetic mapping of a candidate gene was performed with double-digest RAD sequencing using an F2 population derived from a cross between "ShinanoPower" (white) and "Escort" (black). The white seed trait was controlled by a single recessive locus (48.055-50.197 Mbp) in linkage group 7. Using five PCR-based markers and numerous cultivars, eight candidate genes were mapped in the locus. Only the LG7_v8_49.251Mbp_HinfI marker, employing a single-nucleotide mutation in the stop codon of Lsat_1_v5_gn_7_35020.1, was completely linked to seed color phenotype. In addition, the coding region sequences for other candidate genes were identical in the resequence analysis of "ShinanoPower" and "Escort." Therefore, we proposed Lsat_1_v5_gn_7_35020.1 as the candidate gene and designated it as LsMybW (Lactuca sativa Myb White seeds), an ortholog encoding the R2R3-MYB transcription factor in Arabidopsis. When we validated the role of LsMybW through genome editing, LsMybW knockout mutants harboring an early termination codon showed a change in seed color from black to white. Therefore, LsMybW was the allele responsible for the shift in seed color. The development of a robust marker for marker-assisted selection and identification of the gene responsible for white seeds have implications for future breeding technology and physiological analysis.

Metabolism of testosterone and progesterone by cytochrome P450 2C19 allelic variants

CYP2C19 is a member of the human microsomal cytochrome P450 (CYP). Significant variation in CYP2C19 levels and activity can be attributed to polymorphisms in this gene. Wildtype CYP2C19 and 13 mutants (CYP2C19.1B, CYP2C19.5A, CYP2C19.5B, CYP2C19.6, CYP2C19.8, CYP2C19.9, CYP2C19.10, CYP2C19.11, CYP2C19.13, CYP2C19.16, CYP2C19.19, CYP2C19.23, CYP2C19.30, and CYP2C19.33) were coexpressed with NADPH-cytochrome P450 reductase in Escherichia coli. Hydroxylase activity toward testosterone and progesterone was also examined. Ten CYP2C19 variants showed Soret peaks (450 nm) typical of P450 in the reduced CO-difference spectra. CYP2C19.11 and CYP2C19.23 showed higher testosterone 11α, 16α-/17- and progesterone 6β-,21-,16α-/17α-hydroxylase activities than CYP2C19.1B. CYP2C19.6, CYP2C19.16, CYP2C19.19, and CYP2C19.30 showed lower activity than CYP2C19.1B. CYP2C19.9, CYP2C19.10. CYP2C19.13, and CYP2C19.33 showed different hydroxylation activities than CYP2C19.1B. These results indicated that CYP2C19 variants have very different substrate specificities for testosterone and progesterone.

Identification of a 17 kDa protein that is a potentially novel antigen of lettuce-associated respiratory allergy in farmers

BACKGROUND

We have identified and reported a novel antigen, nonprotein-specific secreted EP1-like glycoprotein (51 kDa), for lettuce-related respiratory allergy.

OBJECTIVE

We aimed to identify a novel antigen for lettuce-related respiratory allergy that is different from epidermis-specific secreted EP1-like glycoprotein.

METHODS

Immunoblotting was performed using an immunoglobulin E-specific antibody. The antigen-antibody reaction was confirmed by means of enzyme-linked immunosorbent assaying. LC-MS/MS analysis was carried out to detect a novel protein found in sera from 3 of 13 patients with lettuce-related respiratory allergy. Finally, we purified a novel protein from Escherichia coli.

RESULTS

Immunoblotting assays showed common bands of 17 kDa in the sera of 3 of 13 patients. An enzyme-linked immunosorbent assay confirmed that the patient sera reacted with lettuce latex juice. A 17 kDa protein band that showed antigenic reactivity in 3 of 13 patient sera was identified as a kirola-like protein by LC-MS/MS. In addition, although we purified this protein, we failed to show the inhibitory effect.

CONCLUSION

A 17 kDa protein that is a potentially novel antigen of lettuce-associated respiratory allergy was identified. In further studies, we will focus on purifying this novel protein to diagnose lettuce allergy.

Localization of SNARE proteins in the brain and corpus allatum of Bombyx mori

Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) make up the core machinery that mediates membrane fusion. SNAREs, syntaxin, synaptosome-associated protein (SNAP), and synaptobrevin form a tight SNARE complex that brings the vesicle and plasma membranes together and is essential for membrane fusion. The cDNAs of SNAP-25, VAMP2, and Syntaxin 1A from Bombyx mori were inserted into a plasmid, transformed into Escherichia coli, and purified. We then produced antibodies against the SNAP-25, VAMP2, and Syntaxin 1A of Bombyx mori of rabbits and rats, which were used for immunohistochemistry. Immunohistochemistry results revealed that the expression of VAMP2 was restricted to neurons in the pars intercerebralis (PI), dorsolateral protocerebrum (DL), and central complex (CX) of the brain. SNAP-25 was restricted to neurons in the PI and the CX of the brain. Syntaxin 1A was restricted to neurons in the PI and DL of the brain. VAMP2 co-localized with SNAP-25 in the CX, and with Syntaxin 1A in the PI and DL. VAMP2, SNAP-25, and Syntaxin 1A are present in the CA. Bombyxin-immunohistochemical reactivities (IRs) of brain and CA overlapped with VAMP2-, SNAP-25, and Syntaxin 1A-IRs. VAMP2 and Syntaxin 1A are present in the prothoracicotropic hormone (PTTH)-secretory neurons of the brain.

Evaluation of screening with urine dipsticks and renal ultrasonography for 3-year-olds in Chiba City over 30 years

BACKGROUND

Urinary screening for 3-year-olds cannot adequately detect congenital anomalies of the kidney and urinary tract (CAKUT).

METHODS

Urinary screening for 3-year-olds was investigated over 30 years. Dipsticks for proteinuria, hematuria, glycosuria, leukocyturia, and nitrite at first screening, and dipsticks, urinary sediments, and renal ultrasonography at second screening were performed. Screening results were evaluated.

RESULTS

The positive rates of proteinuria, hematuria, leukocyturia, and nitrite relative to 218,831 children at the first screening were 1.0%, 4.6%, 2.3%, and 0.88%, respectively. Thirty-seven glomerular disease, 122 CAKUT, and 5 urological disease cases were found. We detected 6 stage 3-4 chronic kidney disease (CKD) and 3 end-stage kidney disease cases, including 3 CAKUT, comprising 2 bilateral renal hypoplasia and 1 vesicoureteral reflux (VUR), and 6 glomerular diseases, comprising 4 focal segmental glomerulosclerosis and 2 Alport syndrome. The positive rates relative to 218,831 children and CKD detection rates for each tentative diagnosis of mild hematuria, severe hematuria, proteinuria and hematuria, proteinuria, and suspected urinary tract infection were 1.4% and 0.67%, 0.11% and 3.7%, 0.01% and 28.6%, 0.02% and 45.0%, and 0.08% and 9.7%, respectively. Among 14 VUR cases with significant bacteriuria, 13 were found by leukocyturia, 12 had grade ≥ IV VUR, and 10 had severe renal scars.

CONCLUSIONS

Nine stage 3-5 CKD cases comprising 3 CAKUT and 6 glomerular disease were found by urinary screening of 3-year-olds among 218,831 children. The combination of urine dipsticks including leukocyturia at the first screening and ultrasonography at the second screening appeared useful.

Pre- and Post-Harvest Conditions Affect Polyphenol Content in Strawberry (Fragaria × ananassa)

The strawberry fruit contains abundant polyphenols, such as anthocyanins, flavan-3-ol, and ellagitannin. Polyphenol enrichment improves the quality of strawberries and leads to a better understanding of the polyphenol induction process. We measured the total polyphenol content of strawberry fruits under different growth conditions, developmental stages, and treatment conditions during pre-harvest and post-harvest periods. High fruit polyphenol content was observed in cold treatment, which was selected for further analysis and optimization. A transcriptome analysis of cold-treated fruits suggested that the candidate components of polyphenols may exist in the phenylpropanoid pathway. Coverage with a porous film bag excluded the effects of drought stress and produced polyphenol-rich strawberry fruits without affecting quality or quantity. The degree of stress was assessed using known stress indicators. A rapid accumulation of abscisic acid was followed by an increase in superoxide dismutase and DPPH (2,2-Diphenyl-1-picrylhydrazyl) activity, suggesting that the strawberry fruits responded to cold stress immediately, reaching the climax at around 6 days, a trend consistent with that of polyphenol content. These findings enhance our understanding of the mechanism of post-harvest polyphenol accumulation and the value of strawberries as a functional food.

MLP-PG1, a major latex-like protein identified in Cucurbita pepo, confers resistance through the induction of pathogenesis-related genes

MAIN CONCLUSION

MLP-PG1, identified in Cucurbita pepo, plays a crucial role in resistance against fungal pathogens through the induction of pathogenesis-related genes.

ASTRACT

MLP-PG1, a major latex-like protein (MLP) from zucchini (Cucurbita pepo), was identified as a transporting factor for hydrophobic organic pollutants. MLPs are members of the Bet v 1 family, similar to pathogenesis-related class 10 proteins (PR-10s). However, the biological functions of MLPs remain unclear. Herein, we show that MLP-PG1 induces the expression of pathogenesis-related (PR) genes and indirectly promotes resistance against pathogens. The activity of the MLP-PG1 promoter in leaves of transgenic tobacco plants was significantly enhanced by inoculation with Pseudomonas syringae pv. tabaci. However, MLP-PG1 did not induce direct resistance through RNase activity. Therefore, we examined the possibility that MLP-PG1 is indirectly involved in resistance; indeed, we found that MLP-PG1 induced the expression of defense-related genes. Overexpression of MLP-PG1 highly upregulated PR-2 and PR-5 and decreased the area of lesions caused by Botrytis cinerea in the leaves of transgenic tobacco plants. Our results demonstrate that MLP-PG1 is involved in indirect resistance against plant diseases, especially caused by fungal pathogens, through the induction of PR genes. This study is the first report to show the induction of PR genes by the expression of MLP from the RNA sequencing analysis and the involvement of MLP-PG1 in the resistance.

A CIN-like TCP transcription factor (LsTCP4) having retrotransposon insertion associates with a shift from Salinas type to Empire type in crisphead lettuce (Lactuca sativa L.)

To improve several agronomic traits in crisphead lettuce (Lactuca sativa L.) under high-temperature growth conditions, we investigated the correlation among those traits in multiple cultivars and performed genetic mapping of their causal genes. In a field cultivation test of Empire type (serrated leaf) and Salinas type (wavy leaf) cultivars, Empire type cultivars showed increased tipburn susceptibility and late bolting compared with Salinas type cultivars. We attempted genetic mapping of leaf shape and bolting time by ddRAD-seq using the F2 population derived from a cross between 'VI185' (Empire type) and 'ShinanoGreen' (Salinas type). These analyses suggested that both traits are controlled by a single locus in LG5. Genotyping of 51 commercial lettuce cultivars with a tightly linked marker (LG5_v8_252.743Mbp) at this locus showed an association between its genotype and the serrated leaf phenotype. By further fine mapping and transcriptome analysis, a gene encoding putative CIN-like TCP transcription factor was determined to be a candidate gene at this locus and was designated as LsTCP4. An insertion of retrotransposable element was found in the allele of 'VI185', and its transcript level in the leaves was lower than that in 'ShinanoGreen'. Because shapes of leaf epidermal cells in 'VI185' were similar to those in the TCP family mutant of Arabidopsis thaliana, the leaf shape phenotype was likely caused by reduced expression of LsTCP4. Furthermore, because it is known that the TCP family protein also controls flowering time via interaction with FT in A. thaliana, it was highly possible that LsTCP4 gave pleiotropic effects on both leaf shape and bolting time in lettuce.

Protein S Tokushima: An Abnormal Protein S Found in a Japanese Family with Thrombosis

An abnormal protein S (PS) was found in a Japanese family with a high incidence of thrombosis. The proband is a woman who was born in Tokushima Prefecture. She had superior sagittal sinus thrombosis, thrombophlebitis of the left leg, and thrombosis of the placenta. She had a normal plasma level of free PS antigen but decreased PS activity. Her mother and aunt also had thrombophlebitis of the leg, and together with four other family members also showed a normal level but decreased activity of PS. This suggests that hereditary dysfunction of PS is inherited in this family as an autosomal dominant trait. The proband’s PS appears to have a slightly higher molecular weight than normal PS both in the intact and modified form, suggesting that it has a molecular defect on the carboxyl-terminal side of the thrombin-sensitive site. This abnormal PS with apparently unique characteristics was named PS Tokushima.

Type I Congenital Plasminogen Deficiency Is not a Risk Factor for Thrombosis

The risk of thrombosis in type I congenital plasminogen (PLG) deficiency has been suggested, but is still not confirmed. We studied 40 members of two unrelated families with this disease, and found that 21 were heterozygotes of type I congenital PLG deficiency. Three of them had thrombosis, but the other 18 had no thrombosis. The percentages of family members with no history of thrombosis up to a given age among subjects with type I congenital PLG deficiency and healthy controls were analyzed by the Kaplan-Meier method. No significant difference between the two groups was observed by the generalized Wilcoxon test (p = 0.23). These results suggest that there is no significant correlation between type I congenital PLG deficiency and thrombosis.

Analysis of major paralogs encoding the Fra a 1 allergen based on their organ-specificity in Fragaria × ananassa

Fra a 1 protein in strawberry causes oral allergic syndrome. Over 39 Fra a 1 paralogs have been identified in strawberry genome. Fra a 1.01 is major accumulating protein in edible organs. Strawberry fruits contain allergenic proteins that cause oral allergic syndrome. The hypothesized major allergen is Fra a 1, an ortholog of the birch pollen allergen protein Bet v 1. We organized Fra a 1 genes and analyzed their localizations at the transcriptional and translational levels. In total, 15 new Fra a 1 proteins were identified from the genomic database, increasing the total number of Fra a 1 to 30 proteins encoded by 39 genes. Fra a 1.02 was mostly expressed in receptacles, and Fra a 1.01 in achenes, when analyzed by RNA sequencing. Immunoblotting showed that the Fra a 1.01 protein was broadly accumulated in strawberry organs, while the Fra a 1.02 protein was mostly expressed in receptacles. Recombinant Fra a 1.01 strongly reacted with human IgE. The mRNA and protein expression levels of Fra a 1 did not correlate, indicating the importance of protein levels when evaluating the abundance of allergens in strawberry. Based on the localizations, accumulation levels and reactivity to human IgE, we determined that Fra a 1.01 was the most important allergen, followed by Fra a 1.02, and then other Fra a 1 proteins. The information obtained here will be useful for selecting the target Fra a 1 paralogs when breeding hypoallergenic strawberry.

Localization and functional analysis of the insect-specific RabX4 in the brain of Bombyx mori

Rab proteins are small monomeric GTPases/GTP-binding proteins, which form the largest branch of the Ras superfamily. The different Rab GTPases are localized to the cytosolic face of specific intracellular membranes, where they function as regulators of distinct steps in membrane trafficking. RabX4 is an insect-specific Rab protein that has no close homolog in vertebrates. There is little information about insect-specific Rab proteins. RabX4 was expressed in Escherichia coli and subsequently purified. Antibodies against Bombyx mori RabX4 were produced in rabbits for western immunoblotting and immunohistochemistry. Western blotting of neural tissues revealed a single band, at approximately 26 kD. RabX4-like immunohistochemical reactivity was restricted to neurons of the pars intercerebralis and dorsolateral protocerebrum in the brain. Further immunohistochemical analysis revealed that RabX4 colocalized with Rab6 and bombyxin in the corpus allatum, a neuronal organ that secretes neuropeptides synthesized in the brain into the hemolymph. RabX4 expression in the frontal ganglion, part of the insect stomatogastric nervous system that is found in most insect orders, was restricted to two neurons on the outer region and did not colocalize with allatotropin or Rab6. Furthermore, RNA interference of RabX4 decreased bombyxin expression levels in the brain. These findings suggest that RabX4 is involved in the neurosecretion of a secretory organ in Bombyx mori.

Metabolism of 7-ethoxycoumarin, flavanone and steroids by cytochrome P450 2C9 variants

CYP2C9 is a human microsomal cytochrome P450c (CYP). Much of the variation in CYP2C9 levels and activity can be attributed to polymorphisms of this gene. Wild-type CYP2C9 and mutants were coexpressed with NADPH-cytochrome P450 reductase in Escherichia coli. The hydroxylase activities toward 7-ethoxycoumarin, flavanone and steroids were examined. Six CYP2C9 variants showed Soret peaks (450 nm) typical of P450 in reduced CO-difference spectra. CYP2C9.38 had the highest 7-ethoxycoumarin de-ethylase activity. All the CYP2C9 variants showed lower flavanone 6-hydroxylation activities than CYP2C9.1 (the wild-type). CYP2C9.38 showed higher activities in testosterone 6β-hydroxylation, progesterone 6β-/16α-hydroxylation, estrone 11α-hydroxylation and estradiol 6α-hydroxylation than CYP2C9.1. CYP2C9.40 showed higher testosterone 17-oxidase activity than CYP2C9.1; CYP2C9.8 showed higher estrone 16α-hydroxylase activity and CYP2C9.12 showed higher estrone 11α-hydroxylase activity. CYP2C9.9 and CYP2C9.10 showed similar activities to CYP2C9.1. These results indicate that the substrate specificity of CYP2C9.9 and CYP2C9.10 was not changed, but CYP2C9.8, CYP2C9.12 and CYP2C9.40 showed different substrate specificity toward steroids compared with CYP2C9.1; and especially CYP2C9.38 displayed diverse substrate specificities towards 7-ethoxycoumarin and steroids.

A novel rare variant R292H in RTN4R affects growth cone formation and possibly contributes to schizophrenia susceptibility

Reticulon 4 receptor (RTN4R) plays an essential role in regulating axonal regeneration and plasticity in the central nervous system through the activation of rho kinase, and is located within chromosome 22q11.2, a region that is known to be a hotspot for schizophrenia (SCZ) and autism spectrum disorder (ASD). Recently, rare variants such as copy-number variants and single-nucleotide variants have been a focus of research because of their large effect size associated with increased susceptibility to SCZ and ASD and the possibility of elucidating the pathophysiology of mental disorder through functional analysis of the discovered rare variants. To discover rare variants with large effect size and to evaluate their role in the etiopathophysiology of SCZ and ASD, we sequenced the RTN4R coding exons with a sample comprising 370 SCZ and 192 ASD patients, and association analysis using a large number of unrelated individuals (1716 SCZ, 382 ASD and 4009 controls). Through this mutation screening, we discovered four rare (minor allele frequency <1%) missense mutations (R68H, D259N, R292H and V363M) of RTN4R. Among these discovered rare mutations, R292H was found to be significantly associated with SCZ (P=0.048). Furthermore, in vitro functional assays showed that the R292H mutation affected the formation of growth cones. This study strengthens the evidence for association between rare variants within RTN4R and SCZ, and may shed light on the molecular mechanisms underlying the neurodevelopmental disorder.

Rare genetic variants in CX3CR1 and their contribution to the increased risk of schizophrenia and autism spectrum disorders

CX3CR1, a G protein-coupled receptor solely expressed by microglia in the brain, has been repeatedly reported to be associated with neurodevelopmental disorders including schizophrenia (SCZ) and autism spectrum disorders (ASD) in transcriptomic and animal studies but not in genetic studies. To address the impacts of variants in CX3CR1 on neurodevelopmental disorders, we conducted coding exon-targeted resequencing of CX3CR1 in 370 Japanese SCZ and 192 ASD patients using next-generation sequencing technology, followed by a genetic association study in a sample comprising 7054 unrelated individuals (2653 SCZ, 574 ASD and 3827 controls). We then performed in silico three-dimensional (3D) structural modeling and in vivo disruption of Akt phosphorylation to determine the impact of the detected variant on CX3CR1-dependent signal transduction. We detected a statistically significant association between the variant Ala55Thr in CX3CR1 with SCZ and ASD phenotypes (odds ratio=8.3, P=0.020). A 3D structural model indicated that Ala55Thr could destabilize the conformation of the CX3CR1 helix 8 and affect its interaction with a heterotrimeric G protein. In vitro functional analysis showed that the CX3CR1-Ala55Thr mutation inhibited cell signaling induced by fractalkine, the ligand for CX3CR1. The combined data suggested that the variant Ala55Thr in CX3CR1 might result in the disruption of CX3CR1 signaling. Our results strengthen the association between microglia-specific genes and neurodevelopmental disorders.

Development of genotyping method for functionally relevant variants of cytochromes P450 in cynomolgus macaques

In cynomolgus macaques (Macaca fascicularis), widely used in drug metabolism studies, CYP2C9, CYP2C76, CYP2D6, CYP3A4, and CYP3A5, important drug-metabolizing enzymes, are abundantly expressed in liver and metabolize cytochrome P450 substrates. CYP2C9 (c.334A>C), CYP2C76 (c.449TG>A), CYP2D6 (c.891A>G), CYP3A4 (IVS3 + 1G>del), and CYP3A5 (c.625A>T) substantially influence metabolic activity of enzymes, and thus are important variants in drug metabolism studies. In this study, a real-time PCR method was developed for genotyping these variants. The validity of the methods was verified by genotyping two wild type, two heterozygous, and two homozygous DNAs and was used to genotype 41 cynomolgus macaques (from Cambodia, Indonesia, the Philippines, or Vietnam) for the five variants, along with another important variant CYP2C19 (c.308C>T). The CYP2C9 and CYP2C19 variants were found only in Cambodian and Vietnamese animals, while the CYP2C76 and CYP2D6 variants were found only in Indonesian and Philippine animals. The CYP3A4 and CYP3A5 variants were not found in any of the animals analyzed. Mauritian animals, genotyped using next-generation sequencing data for comparison, possessed the CYP2C19 and CYP2D6 variants, but not the other variants. These results indicated differences in prevalence of these important variants among animal groups. Therefore, the genotyping tool developed is useful for drug metabolism studies using cynomolgus macaques.

High-resolution copy number variation analysis of schizophrenia in Japan

Recent schizophrenia (SCZ) studies have reported an increased burden of de novo copy number variants (CNVs) and identified specific high-risk CNVs, although with variable phenotype expressivity. However, the pathogenesis of SCZ has not been fully elucidated. Using array comparative genomic hybridization, we performed a high-resolution genome-wide CNV analysis on a mainly (92%) Japanese population (1699 SCZ cases and 824 controls) and identified 7066 rare CNVs, 70.0% of which were small (<100 kb). Clinically significant CNVs were significantly more frequent in cases than in controls (odds ratio=3.04, P=9.3 × 10^-9, 9.0% of cases). We confirmed a significant association of X-chromosome aneuploidies with SCZ and identified 11 de novo CNVs (e.g., MBD5 deletion) in cases. In patients with clinically significant CNVs, 41.7% had a history of congenital/developmental phenotypes, and the rate of treatment resistance was significantly higher (odds ratio=2.79, P=0.0036). We found more severe clinical manifestations in patients with two clinically significant CNVs. Gene set analysis replicated previous findings (e.g., synapse, calcium signaling) and identified novel biological pathways including oxidative stress response, genomic integrity, kinase and small GTPase signaling. Furthermore, involvement of multiple SCZ candidate genes and biological pathways in the pathogenesis of SCZ was suggested in established SCZ-associated CNV loci. Our study shows the high genetic heterogeneity of SCZ and its clinical features and raises the possibility that genomic instability is involved in its pathogenesis, which may be related to the increased burden of de novo CNVs and variable expressivity of CNVs.

Secondary pseudohypoaldosteronism causing cardiopulmonary arrest and cholelithiasis

A 4-month-old boy presented with cardiopulmonary arrest on arrival after a brief period of lethargy. Laboratory examination indicated severe hyperkalemia, hyponatremia, metabolic acidosis, and slightly elevated C-reactive protein. Whole body computed tomography identified left-dominant hydronephrosis, hydroureter and cholelithiasis. Despite cardiac arrest >30 min, he was successfully resuscitated and treated with therapeutic hypothermia. Escherichia coli was detected on urine culture. Renal ultrasound showed bilateral hydronephrosis, grade II in the right and grade IV in the left. Retrospective analysis of the blood sample at admission indicated a high level of aldosterone. The patient recovered almost fully with no electrolyte imbalance and normal plasma renin and aldosterone, leading to the diagnosis of secondary pseudohypoaldosteronism associated with bilateral infected hydronephrosis. In this case, cholelithiasis, which may account for chronic dehydration, was a diagnostic clue in the absence of information of pre-existing situations.

Homoeologous chromosomes of Xenopus laevis are highly conserved after whole-genome duplication

It has been suggested that whole-genome duplication (WGD) occurred twice during the evolutionary process of vertebrates around 450 and 500 million years ago, which contributed to an increase in the genomic and phenotypic complexities of vertebrates. However, little is still known about the evolutionary process of homoeologous chromosomes after WGD because many duplicate genes have been lost. Therefore, Xenopus laevis (2n=36) and Xenopus (Silurana) tropicalis (2n=20) are good animal models for studying the process of genomic and chromosomal reorganization after WGD because X. laevis is an allotetraploid species that resulted from WGD after the interspecific hybridization of diploid species closely related to X. tropicalis. We constructed a comparative cytogenetic map of X. laevis using 60 complimentary DNA clones that covered the entire chromosomal regions of 10 pairs of X. tropicalis chromosomes. We consequently identified all nine homoeologous chromosome groups of X. laevis. Hybridization signals on two pairs of X. laevis homoeologous chromosomes were detected for 50 of 60 (83%) genes, and the genetic linkage is highly conserved between X. tropicalis and X. laevis chromosomes except for one fusion and one inversion and also between X. laevis homoeologous chromosomes except for two inversions. These results indicate that the loss of duplicated genes and inter- and/or intrachromosomal rearrangements occurred much less frequently in this lineage, suggesting that these events were not essential for diploidization of the allotetraploid genome in X. laevis after WGD.

Quantitative autistic traits ascertained in a national survey of 22 529 Japanese schoolchildren

OBJECTIVE

Recent epidemiologic studies worldwide have documented a rise in prevalence rates for autism spectrum disorders (ASD). Broadening of diagnostic criteria for ASD may be a major contributor to the rise in prevalence, particularly if superimposed on an underlying continuous distribution of autistic traits. This study sought to determine the nature of the population distribution of autistic traits using a quantitative trait measure in a large national population sample of children.

METHOD

The Japanese version of the Social Responsiveness Scale (SRS) was completed by parents on a nationally representative sample of 22 529 children, age 6-15.

RESULTS

Social Responsiveness Scale scores exhibited a skewed normal distribution in the Japanese population with a single-factor structure and no significant relation to IQ within the normal intellectual range. There was no evidence of a natural 'cutoff' that would differentiate populations of categorically affected children from unaffected children.

CONCLUSION

This study provides evidence of the continuous nature of autistic symptoms measured by the SRS, a validated quantitative trait measure. The findings reveal how paradigms for diagnosis that rest on arbitrarily imposed categorical cutoffs can result in substantial variation in prevalence estimation, especially when measurements used for case assignment are not standardized for a given population.

Mushroom body-preferential expression of proteins/genes involved in endoplasmic reticulum Ca(2+)-transport in the worker honeybee (Apis mellifera L.) brain

To identify the molecular characteristics specific to the mushroom body (MB, a higher processing centre) neurones in the honeybee brain, we previously used proteomics to identify proteins that are preferentially expressed in these MBs. Here we continued our proteomic analysis to show that reticulocalbin, which is involved in endoplasmic reticulum (ER) Ca(2+) transport, is also preferentially expressed in the MBs in the honeybee brain. Gene expression analysis revealed that reticulocalbin is preferentially expressed in the large-type Kenyon cells, which are MB-intrinsic neurones. In addition, the gene for the ryanodine receptor, which is also involved in ER Ca(2+) transport, was also preferentially expressed in the large-type Kenyon cells. In contrast, the expression of three other ER-related genes, protein disulphide isomerase, sec61 and erp60, was not enriched in the MBs. These findings further support the notion that the function of ER Ca(2+)-signalling, but not the mere intracellular density of ER, is specifically enhanced in the large-type Kenyon cells in the honeybee brain.

Quantification of interferon, interleukin, and Toll-like receptor 7 mRNA in quail splenocytes using real-time PCR

Japanese quail (Coturnix japonica) are farmed worldwide as poultry. Quail have been used as experimental animals in various scientific fields, but their immunological characteristics have not been well characterized. In this study, to develop a method for analyzing the innate immune response of quail to infectious pathogens, we determined the nucleotide sequences of major interleukins (IL) and Toll-like receptor (TLR)-7 of quail and developed quantitative real-time PCR assays. The nucleotide sequences of quail IL-1β, IL-4, IL-6, IL-8, IL-10, IL-12a, IL-12b, IL-13, IL-18, and TLR-7 were determined based on the sequences of the chicken genes. Specific primers for each of these genes and previously reported interferon (IFN)-α, IFN-γ, and IL-2 genes were designed for quantitative real-time PCR. Standard curves for quantification were established using serial dilutions of external standard plasmids containing real-time PCR products. Then, real-time PCR was performed to monitor the kinetics of quail immune-related gene expression induced in splenocytes stimulated with concanavalin A. After amplification, the r(2) values of the standard curves for all target genes were above 0.980. Melting analysis of real-time PCR revealed specific amplification of each gene that could be visualized clearly as a single peak of melting temperature in a melt peak chart. These data show that the mRNA expressions of quail immune-related genes can be accurately quantified using this real-time PCR assay. In this study, we showed the nucleotide sequences of several quail cytokine mRNA and constructed the quantitative real-time PCR for quail immune-related genes.

Rab14 from Bombyx mori (Lepidoptera: Bombycidae) shows ATPase activity

Rab GTPases are essential for vesicular transport, whereas adenosine triphosphate (ATP) is the most important and versatile of the activated carriers in the cell. But there are little reports to clarify the connection between ATP and Rab GTPases. A cDNA clone (Rab14) from Bombyx mori was expressed in Escherichia coli as a glutathione S-transferase fusion protein and purified. The protein bound to [(3)H]-GDP and [(35)S]-GTPgammaS. Binding of [(35)S]-GTPgammaS was inhibited by guanosine diphosphate (GDP), guanosine triphosphate (GTP) and ATP. Rab14 showed GTP- and ATP-hydrolysis activity. The Km value of Rab14 for ATP was lower than that for GTP. Human Rab14 also showed an ATPase activity. Furthermore, bound [(3)H]-GDP was exchanged efficiently with GTP and ATP. These results suggest that Rab14 is an ATPase as well as GTPase and gives Rab14 an exciting integrative function between cell metabolic status and membrane trafficking.

Cynomolgus monkey CYPs: a comparison with human CYPs

Characteristics of twelve cytochromes P450 (CYPs) from cynomolgus monkeys were compared with those of human CYPs that play an important role in drug metabolism. Eleven members of CYP1A, CYP2A, CYP2C, CYP2D, CYP2E, and CYP3A subfamilies from cynomolgus monkeys exhibited a high degree of homologies (more than 90%) in cDNA and amino acid sequences with corresponding human CYPs, and catalysed typical reactions of corresponding human CYPs. One member of the cynomolgus monkey CYP2C subfamily, CYP2C76, exhibited a lower homology (around 70%) in amino acid sequences with other cynomolgus monkey and human CYP2C subfamilies. CYP2C76 catalysed typical CYP2C substrates with low activities, and has not been found in humans. CYPs identified in cynomolgus monkeys were similar to CYP1A1, CYP1A2, CYP2A6, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP3A4, and CYP3A5 in humans. These results indicate that cynomolgus monkeys express CYPs similar to human CYPs that are important in drug metabolism.

Karyological characterization of the butterfly lizard (Leiolepis reevesii rubritaeniata, Agamidae, Squamata) by molecular cytogenetic approach

Karyological characterization of the butterfly lizard (Leiolepis reevesii rubritaeniata) was performed by conventional Giemsa staining, Ag-NOR banding, FISH with the 18S-28S and 5S rRNA genes and telomeric (TTAGGG)n sequences, and CGH. The karyotype was composed of 2 distinct components, macrochromosomes and microchromosomes, and the chromosomal constitution was 2n = 2x = 36 (L(4)(m) + L(2)(sm) + M(2)(m) + S(4)(m) + 24 microchromosomes). NORs and the 18S-28S rRNA genes were located at the secondary constriction of the long arm of chromosome 1, and the 5S rRNA genes were localized to the pericentromeric region of chromosome 6. Hybridization signals of (TTAGGG)n sequences were observed at the telomeric ends of all chromosomes and interstitially at the same position as the 18S-28S rRNA genes, suggesting that in the Leiolepinae tandem fusion probably occurred between chromosome 1 and a microchromosome where the 18S-28S rRNA genes were located. CGH analysis, however, failed to identify sex chromosomes, suggesting that this species may have a TSD system or exhibit GSD with morphologically undetectable cryptic sex chromosomes. Homologues of 6 chicken Z-linked genes (ACO1/IREBP, ATP5A1, CHD1, DMRT1, GHR, RPS6) were all mapped to chromosome 2p in the same order as on the snake chromosome 2p.

CYP2C76-mediated species difference in drug metabolism: A comparison of pitavastatin metabolism between monkeys and humans

The monkey is often used to predict metabolism of drugs in humans since it generally shows a metabolic pattern similar to humans. However, metabolic profiles different from humans are occasionally seen in monkeys for some drugs including pitavastatin. Recently, we have successfully identified a monkey-specific cytochrome P450 (CYP) 2C76, which possibly accounts for a species difference between monkeys and humans because of its sequence and functional uniqueness. The present study on the role of CYP2C76 and other monkey CYP2Cs in pitavastatin metabolism, as an example, has revealed that CYP2C76 is important for the metabolism of the lactone form, indicating a major role of CYP2C76 for the difference in the metabolism of pitavastatin and possibly other drugs between monkeys and humans. The current investigation on the involvement of CYP2C76 in the metabolism of other drugs is expected to reveal further the further importance of this monkey-specific drug-metabolizing enzyme.

Genomic structure and transcript variants of the bovine DAZL gene

The Deleted in AZoospermia Like (DAZL) gene is a member of the DAZ family and encodes an RNA-binding protein that is expressed in prenatal and postnatal germ cells of males and females. In the human, there are five highly-related members in the DAZ family, four (DAZ1-4) on the Y chromosome and one (DAZL) on an autosome (HSA3). Mutations in these genes have been linked to severe spermatogenic failure and infertility in men. In the present study, we have cloned and characterized the bovine DAZL (bDAZL) gene. The full-length bDAZL cDNA is predicted to encode a protein of 295 amino acids with an RNA recognition motif. The deduced protein sequence of bDAZL is 96 and 97% similar to human and mouse DAZL, respectively. Fluorescence in situ hybridization (FISH) maps bDAZL to the distal region on BTA1q. The bDAZL gene consists of 11 exons and 10 introns. A bDAZL pseudogene was identified on BTA16. Expression analysis of bDAZL in 13 different tissues by RT-PCR shows that two transcripts, variant 1 (2,996 bp) and variant 2 (1,373 bp), of the bDAZL gene are detected only in testis mRNA. The variants probably result from alternative RNA splicing as variant 1 contains an additional 1,623-bp insertion in the 3' UTR. Our results lay the groundwork for possible single nucleotide polymorphism (SNP) and functional studies of the DAZL gene in cattle.