Skin transcriptome profiling of Changthangi goats highlights the relevance of genes involved in Pashmina production

Molecular insights into Pashmina fiber production: comparative skin transcriptomic analysis of Changthangi goats and sheep

Ladakh, one of the highest inhabited regions globally, hosts the unique Changthangi goat, renowned for producing Pashmina, the world's most luxurious natural fiber. In comparison, the fiber derived from Changthangi sheep is considered next only to Pashmina. This research endeavors to compare the skin transcriptome profiles of Changthangi goats and Changthangi sheep, aiming to discern the molecular determinants behind the recognition of Changthangi goats as the source of Pashmina. Drawing upon previously conducted studies, a collective of 225 genes correlated with fiber characteristics were extracted from the differentially expressed genes noticed between the two species (p-value of ≤ 0.05 and a log2 fold change of ≥ 1.5). These genes were analyzed using DAVID software to understand their biological functions and to identify enriched KEGG and Reactome pathways. The protein-protein interaction networks were constructed using Cytoscape, cytoHubba, and STRING to focus on key genes and infer their biological significance. Comparative transcriptome analysis revealed significantly higher expression of genes involved in signaling pathways like Wnt, MAPK, PI3K-Akt, Hedgehog, associated with fiber development and quality in Changthangi goats. These pathways play crucial roles in hair follicle (HF) formation, maintenance of epidermal stem cells, and fiber characteristics. Findings also highlight the enrichment of cell adhesion molecules and ECM-receptor interaction, emphasizing their roles in HF structure, growth, and signaling. This investigation offers an in-depth understanding of the molecular intricacies governing Pashmina production in Changthangi goats, providing valuable insights into their unique genetic makeup and underlying mechanisms influencing the exceptional quality of Pashmina fibers.

Skeletal muscle transcriptomics of sheep acclimated to cold desert and tropical regions identifies genes and pathways accentuating their diversity

The current study attempts to investigate the differences in gene expression in longissimus thoracis muscles between sheep breeds acclimated to diverse environments. Changthangi sheep inhabits the cold arid plateau of Ladakh, at an altitude above 3000 m with prevalence of rarefied atmosphere. Muzzafarnagri sheep, on the other hand is found in the sub-tropical hot and humid plains at an altitude of about 250 m. Comparative transcriptomics was used to provide a molecular perspective of the differential adaptation of the two breeds. RNA sequencing data was generated from four biological replicates of the longissimus thoracis muscles from both breeds. The common genes expressed in both breeds were involved in muscle contraction and muscle fibre organization. The most significant pathways enriched in Changthangi muscles were glycogen metabolism, reduction of cytosolic Ca++ levels and NFE2L2 regulating anti-oxidant, while those in Muzzafarnagri were extracellular matrix organization and collagen formation. The hub genes identified in Changthangi were involved in hematopoiesis and HIF signaling pathway, suggesting the molecular acclimatization of Changthangi to the high altitude cold desert of Ladakh. The nodal genes discovered in Muzzafarnagri sheep were associated with the extracellular matrix which accentuates its significance in the development, growth and repair of muscles. The observed transcriptomic differences underscore the morphological and adaptive disparity between the two breeds. The candidate genes and pathways identified in this study will form the basis for future research on adaptation to high altitude and body size in small ruminants.

Genetic insights into fiber quality, coat color and adaptation in Changthangi and Muzzafarnagri sheep: A comparative skin transcriptome analysis

Changthangi sheep, which inhabit the high-altitude regions of Ladakh, are known for their fine fiber production and are characterized by grey skin and either black or white coats. In contrast, Muzzafarnagri sheep from the plains of Uttar Pradesh produce coarse wool and have white skin and coats. We conducted comparative global gene expression profiling on four biological replicates of skin from each breed. Notably, our analysis identified 149 up-regulated genes and 2,139 down-regulated genes in Changthangi sheep compared to Muzzafarnagri sheep, with a p-adjusted value (padj) of ≤0.05 and a Log2 fold change of ≥1.5. Gene Ontology analysis of the up-regulated genes revealed an enrichment of terms related to melanin biosynthesis and developmental pigmentation. Additionally, enriched KEGG pathways included tyrosine metabolism and metabolic pathways. Among the melanogenesis-related genes that exhibited higher expression in Changthangi sheep were TYR, TYRP1, DCT, SLC45A2, PMEL, MLANA, and OCA2. These findings confirm melanin's role in both the animals' black coat color and UV protection at high-altitude. Furthermore, we observed more pronounced expression of genes related to fiber quality, namely KRTAP6, KRTAP7, KRTAP13, and KRTAP2, in the fine wool-producing sheep from Ladakh. The results of the RNA sequencing were validated using real-time PCR on 10 genes governing fiber quality and coat color, with ACTB and PPIB serving as reference genes. In conclusion, our comparative skin transcriptome analysis of Changthangi and Muzzafarnagri sheep sheds light on the genetic differences associated with distinct phenotypic traits and environmental adaptability, offering valuable insights into the underlying mechanisms.

Morphometric characteristics and microsatellite markers based diversity and differentiation recognizes the first prospective cattle breed from the Jharkhand state of India

India is bestowed with immense cattle biodiversity with 50 registered breeds. However, the majority (59.3%) is yet not characterized. Identification and characterization are the gateways to the management of prized indigenous resources. Present research described a unique cattle population of Jharkhand state, managed under a traditional low-input, low-output system. It was characterized by morphological traits, performance parameters, and management practices. Animals have the characteristic pre-scapular location of the hump. Genetic variation within this population and its differentiation with the six closely distributed cattle breeds were evaluated using FAO recommended microsatellite markers. Jharkhandi cattle have substantial genetic variation based on gene diversity (>0.6) and the average number of alleles per locus (>8). The population did not suffer from a genetic bottleneck in the recent past. Pairwise Nei's genetic distance, phylogenetic relationship, population differentiation, and the correct assignment of all the animals to self group substantiated its separate genetic identity. Since gene flow (Nm = 2.8-7.32) was identified and admixture was indicated by the Bayesian analysis there is a pressing need for scientific management of this population. Results endow authorities with critical information for registering a new Indian cattle breed (Medini) that contributes to the food security, livelihood, and economic sustainability of rural tribal households.

Construction of a circRNA- lincRNA-lncRNA-miRNA-mRNA ceRNA regulatory network identifies genes and pathways linked to goat fertility

Background: There is growing interest in the genetic improvement of fertility traits in female goats. With high-throughput genotyping, single-cell RNA sequencing (scRNA-seq) is a powerful tool for measuring gene expression profiles. The primary objective was to investigate comparative transcriptome profiling of granulosa cells (GCs) of high- and low-fertility goats, using scRNA-seq. Methods: Thirty samples from Ji'ning Gray goats (n = 15 for high fertility and n = 15 for low fertility) were retrieved from publicly available scRNA-seq data. Functional enrichment analysis and a literature mining approach were applied to explore modules and hub genes related to fertility. Then, interactions between types of RNAs identified were predicted, and the ceRNA regulatory network was constructed by integrating these interactions with other gene regulatory networks (GRNs). Results and discussion: Comparative transcriptomics-related analyses identified 150 differentially expressed genes (DEGs) between high- and low-fertility groups, based on the fold change (≥5 and ≤-5) and false discovery rate (FDR <0.05). Among these genes, 80 were upregulated and 70 were downregulated. In addition, 81 mRNAs, 58 circRNAs, 8 lincRNAs, 19 lncRNAs, and 55 miRNAs were identified by literature mining. Furthermore, we identified 18 hub genes (SMAD1, SMAD2, SMAD3, SMAD4, TIMP1, ERBB2, BMP15, TGFB1, MAPK3, CTNNB1, BMPR2, AMHR2, TGFBR2, BMP4, ESR1, BMPR1B, AR, and TGFB2) involved in goat fertility. Identified biological networks and modules were mainly associated with ovary signature pathways. In addition, KEGG enrichment analysis identified regulating pluripotency of stem cells, cytokine-cytokine receptor interactions, ovarian steroidogenesis, oocyte meiosis, progesterone-mediated oocyte maturation, parathyroid and growth hormone synthesis, cortisol synthesis and secretion, and signaling pathways for prolactin, TGF-beta, Hippo, MAPK, PI3K-Akt, and FoxO. Functional annotation of identified DEGs implicated important biological pathways. These findings provided insights into the genetic basis of fertility in female goats and are an impetus to elucidate molecular ceRNA regulatory networks and functions of DEGs underlying ovarian follicular development.

Novel Insights to Assess Climate Resilience in Goats Using a Holistic Approach of Skin-Based Advanced NGS Technologies

A novel study was conducted to elucidate heat-stress responses on a number of hair- and skin-based traits in two indigenous goat breeds using a holistic approach that considered a number of phenotypic and genomic variables. The two goat breeds, Kanni Aadu and Kodi Aadu, were subjected to a simulated heat-stress study using the climate chambers. Four groups consisting of six goats each (KAC, Kaani Aadu control; KAH, Kanni Aadu heat stress; KOC, Kodi Aadu control; and KOH, Kodi Aadu heat stress) were considered for the study. The impact of heat stress on caprine skin tissue along with a comparative assessment of the thermal resilience of the two goat breeds was assessed. The variables considered were hair characteristics, hair cortisol, hair follicle quantitative PCR (qPCR), sweating (sweating rate and active sweat gland measurement), skin histometry, skin-surface infrared thermography (IRT), skin 16S rRNA V3-V4 metagenomics, skin transcriptomics, and skin bisulfite sequencing. Heat stress significantly influenced the hair fiber characteristics (fiber length) and hair follicle qPCR profile (Heat-shock protein 70 (HSP70), HSP90, and HSP110). Significantly higher sweating rate, activated sweat gland number, skin epithelium, and sweat gland number (histometry) were observed in heat stressed goats. The skin microbiota was also observed to be significantly altered due to heat stress, with a relatively higher alteration being noticed in Kanni Aadu goats than in Kodi Aadi goats. Furthermore, the transcriptomics and epigenetics analysis also pointed towards the significant impact of heat stress at the cellular and molecular levels in caprine skin tissue. The higher proportion of differentially expressed genes (DEGs) along with higher differentially methylated regions (DMRs) in Kanni Aadu goats due to heat stress when compared to Kodi Aadu goats pointed towards the better resilience of the latter breed. A number of established skin, adaptation, and immune-response genes were also observed to be significantly expressed/methylated. Additionally, the influence of heat stress at the genomic level was also predicted to result in significant functional alterations. This novel study thereby highlights the impact of heat stress on the caprine skin tissue and also the difference in thermal resilience exhibited by the two indigenous goat breeds, with Kodi Aadu goats being more resilient.

Characterization of Growth Secondary Hair in Min Pig Activated by Follicle Stem Cell Stimulated by Wnt and BMP Signaling Pathway

In China, the national-level protected pig, the Min pig, is characterized by the development of secondary hairs and hair follicles in winter. Factors that dominate the genotype in the growth of secondary hairs are not clear through the concrete cell signaling pathways. This study compared hair phenotypes based on morphological structure, transcriptomics, and potential targeting molecules in the breeds of Min, Berkshire, and Yorkshire pigs. The results indicated that Min pigs have specific characteristics for the growth of secondary hairs compared with the Berkshire and Yorkshire pigs. The transcriptome analyses and quantitative reverse transcription-polymerase chain reaction results revealed that secondary hair growth was activated by follicle stem cells. The specific inhibitors of Wnt and BMP were studied using respective signals. The density of follicles, activity of follicle stem cells, and relative gene expression results have shown that Wnt and BMP stimulate the activity of follicle stem cells, and the Wnt signaling molecule has a significantly better effect than the BMP signaling molecule on stem cells. Wnt and BMP can promote the growth of local secondary hair and gene expression. Therefore, this study was conducted to verify the development mechanisms of secondary hairs, which have potential applications in laboratory animals and comparative medicine.

Validation of stable reference genes in peripheral blood mononuclear cells for expression studies involving vector-borne haemoparasitic diseases in bovines

Normalization of gene expression data using appropriate reference genes is critical to diminish any technical bias in an experiment involving quantitative real-time PCR (qPCR). To the best of our knowledge, this is the first report offering a systematic assessment of 14 potential reference genes (RPLP0, ACTB, RPS28, YWHAZ, SDHA, PPIA, RPS9, RPS15, UXT, GAPDH, B2M, BACH1, HMBS, and PPIB) for the identification of the most stable normalizers for qPCR of target genes in peripheral blood mononuclear cells (PBMCs) of bovines for vector-borne haemoparasitic diseases such as anaplasmosis, babesiosis, theileriosis, and trypanosomiasis. A total of 38 blood samples were collected from healthy as well as diseased cattle and buffaloes representing different haemoparasitic diseases. RNA isolated from the PBMCs was subjected to qPCR for the 14 prospective internal control genes. The comprehensive ranking of the genes was accomplished by the RefFinder tool that integrates the results of three algorithms (geNorm, NormFinder, and BestKeeper) and the comparative C_T method. RPS15, B2M, and GAPDH were ranked to be the most stable genes, whereas, PPIA and HMBS emerged to be the least suitable genes. Validation of the selected reference genes by the qPCR analysis of two immunity genes, ISG15 and GPX7 was congruent with the observations of this study. We recommend that a panel of three reference genes including RPS15, B2M, and GAPDH could prove useful in delineating the transcriptional landscape of PBMCs for vector-borne haemoparasitic diseases in bovines.

Cashmere production, skin characteristics, and mutated genes in crimped cashmere fibre goats

A subpopulation of Yanshan cashmere goats with crimped fibre has emerged in a closed population in recent years, but little is known about differences in cashmere production performance, skin characteristics, and fibre-style-related genes between goats with different cashmere fibre styles. Therefore, the aim of this study was to investigate fibre characteristics, cashmere yield, hair follicle traits, and fibre-style-related genes in cashmere goats with the two cashmere fleece styles-non-crimped and crimped. Based on the cashmere fibre type, 80 six-month-old female Yanshan cashmere goats were used in this study: 40 goats with non-crimped fleece (NCF) and 40 with crimped fleece (CF). The growth performance and cashmere production of the goats were recorded. Skin samples were collected to determine hair follicle traits and gene sequencing. The results indicated that there were no differences in initial live weight, final live weight, average daily feed intake, and average daily gain between the two groups of goats (P > 0.05). The total yield of cashmere and the stretched length of fibre of the CF goats were higher (P < 0.01 and P < 0.05, respectively) and fibre diameter was lower (P < 0.05) than that of the NCF goats. There were no between-group differences in the density and activity of primary and secondary hair follicles, secondary-to-primary fibre ratio, depth of primary follicles, or epidermal thickness. However, the depth of secondary follicles and dermal thickness were higher (P < 0.05) in NCF goats than in CF goats. There were mutations in the KRT5, KAP8, KRT8, KRT74, KRT34, KRT1, KRT71, KRT6A, KAP6, KRT81, and KRT83 genes, four of which caused amino acid changes. The allele and genotype frequencies of base mutations in the KRT5, KAP8, KRT34, KRT1, KRT6A, KRT81, and KRT83 genes were different in the NCF and CF goats (P < 0.05). The distribution and content of the secondary structure elements and tertiary structures of proteins differed between the wide-type and mutated KRT1 and KRT6A proteins. KRT1, KRT6A, KRT71, and TGFα mRNA expression levels were significantly higher in CF goats than in NCF goats (P < 0.05). It is concluded that cashmere goats that have fleece with crimped fibres produce a greater yield of fleece with finer diameter fibres than those with conventional straight cashmere fibres. These differences in fibre properties may be associated with mutations in the genes coding for KRT1 and KRT6A.

Integrated analysis of lncRNAs and mRNAs by RNA-Seq in secondary hair follicle development and cycling (anagen, catagen and telogen) of Jiangnan cashmere goat (Capra hircus)

BACKGROUND

Among the world's finest natural fiber composites is derived from the secondary hair follicles (SHFs) of cashmere goats yield one of the world's best natural fibres. Their development and cycling are characterized by photoperiodism with diverse, well-orchestrated stimulatory and inhibitory signals. Long non-coding RNA (lncRNAs) and mRNAs play important roles in hair follicle (HF) development. However, not many studies have explored their specific functions in cashmere development and cycling. This study detected mRNAs and lncRNAs with their candidate genes and related pathways in SHF development and cycling of cashmere goat. We utilized RNA sequencing (RNA-Seq) and bioinformatics analysis on lncRNA and mRNA expressions in goat hair follicles to discover candidate genes and metabolic pathways that could affect development and cycling (anagen, catagen, and telogen).

RESULTS

We identified 228 differentially expressed (DE) mRNAs and 256 DE lncRNA. For mRNAs, catagen and anagen had 16 upregulated and 35 downregulated DEGs, catagen and telogen had 18 upregulated and 9 downregulated DEGs and telogen and anagen had 52 upregulated and 98 downregulated DEGs. LncRNA witnessed 22 upregulated and 39 downregulated DEGs for catagen and anagen, 36 upregulated and 29 downregulated DEGs for catagen and telogen as well as 66 upregulated and 97 downregulated DEGs for telogen and anagen. Several key genes, including MSTRG.5451.2, MSTRG.45465.3, MSTRG.11609.2, CHST1, SH3BP4, CDKN1A, GAREM1, GSK-3β, DEFB103A KRTAP9-2, YAP1, S100A7A, FA2H, LOC102190037, LOC102179090, LOC102173866, KRT2, KRT39, FAM167A, FAT4 and EGFL6 were shown to be potentially important in hair follicle development and cycling. They were related to, WNT/β-catenin, mTORC1, ERK/MAPK, Hedgehog, TGFβ, NFkB/p38MAPK, caspase-1, and interleukin (IL)-1a signaling pathways.

CONCLUSION

This work adds to existing understanding of the regulation of HF development and cycling in cashmere goats via lncRNAs and mRNAs. It also serves as theoretical foundation for future SHF research in cashmere goats.

miR-129-5p Participates in Hair Follicle Growth by Targeting HOXC13 in Rabbit

Mammalian hair formation is critically determined by the growth of hair follicles (HF). MiRNAs are crucial in the periodic development of hair follicles; they maintain epidermal homeostasis by targeting genes and influencing the activity of signaling pathways and related regulators. Our study discovered miR-129-5p to be overexpressed in the skin of Angora rabbits during catagen, and was negatively correlated with HOXC13 expression (Pearson’s R = −0.313, p < 0.05). The dual-Luciferase reporter gene detection system and Western blotting confirmed that miR-129-5p targeted HOXC13. In addition, miR-129-5p overexpression was found to significantly inhibit the expression of hair follicle development-related genes (HFDRGs), such as BCL2, WNT2, CCND1, and LEF1 (p < 0.01), and promoted the expression of SFRP2, TGF-β1, and FGF2 (p < 0.01), which was the same as the knockdown of HOXC13. In contrast, the knockout of miR-129-5p was the opposite, and it demonstrated similar results to the overexpression of HOXC13. CCK8 and flow cytometry demonstrated that miR-129-5p mimics significantly promoted the apoptosis of dermal papilla cells (DPCs) and inhibited proliferation (p < 0.01), while the inhibitor was found to reduce the apoptosis of DPCs and promote proliferation (p < 0.01). These results showed that miR-129-5p can participate in the periodic development of HF by targeting HOXC13, and it can induce apoptosis and inhibit proliferation of DPCs. These results will help to understand the role and mechanism of miR-129-5p in the periodic development of HF, and will provide support for subsequent studies, not only providing a theoretical basis for genetically improving the quality of hair in animals in the future, but also a new theory and method for diagnosing and treating hair loss in humans.

Transcriptomics analysis of cashmere fineness functional genes

Liaoning cashmere goat (LCG) is a famous cashmere goat breed in China. Cashmere fineness, as an important index to evaluate cashmere quality, is also one of the problems to be improved for Liaoning cashmere goats. Transcriptome studies all mRNA transcribed by a specific tissue or cell in a certain period. It is a key link in the study of gene expression regulation. It plays an important role in the analysis of biological growth and disease. Transcriptome is spatio-temporal specific, that is, gene expression varies in different tissues or at different times. Three coarser and three fine LCG skin samples were sequenced by RNA-seq technology, and a total of 427 differentially expressed genes were obtained, including 291 up-regulated genes and 136 down-regulated genes. In the experiment, we screened out 16 genes that had significant differences in the expression of coarse and fine cashmere of Liaoning cashmere goats, so it was inferred that these 16 genes might have regulatory effects on cashmere fineness. Moreover, GO gene set enrichment analysis revealed that differential genes mainly consist of immune response, MHC protein complex, Heme binding and other pathways. KEGG analysis showed that transplant-versus-host disease and allograft rejection were the main pathways of differential genes.

Perinatal Exposure to Nicotine Alters Sperm RNA Profiles in Rats

Perinatal exposure to smoking has been associated with childhood asthma, one of the most common pediatric conditions affecting millions of children globally. Of great interest, this disease phenotype appears heritable as it can persist across multiple generations even in the absence of persistent exposure to smoking in subsequent generations. Although the molecular mechanisms underlying childhood asthma induced by perinatal exposure to smoking or nicotine remain elusive, an epigenetic mechanism has been proposed, which is supported by the data from our earlier analyses on germline DNA methylation (5mC) and histone marks (H3 and H4 acetylation). To further investigate the potential epigenetic inheritance of childhood asthma induced by perinatal nicotine exposure, we profiled both large and small RNAs in the sperm of F1 male rats. Our data revealed that perinatal exposure to nicotine leads to alterations in the profiles of sperm-borne RNAs, including mRNAs and small RNAs, and that rosiglitazone, a PPARγ agonist, can attenuate the effect of nicotine and reverse the sperm-borne RNA profiles of F1 male rats to close to placebo control levels.

Identification of the Key Genes Associated with the Yak Hair Follicle Cycle

The development of hair follicles in yak shows significant seasonal cycles. In our previous research, transcriptome data including mRNAs and lncRNAs in five stages during the yak hair follicles (HFs) cycle were detected, but their regulation network and the hub genes in different periods are yet to be explored. This study aimed to screen and identify the hub genes during yak HFs cycle by constructing a mRNA-lncRNA co-expression network. A total of 5000 differently expressed mRNA (DEMs) and 729 differently expressed long noncoding RNA (DELs) were used to construct the co-expression network, based on weighted genes co-expression network analysis (WGCNA). Four temporally specific modules were considered to be significantly associated with the HFs cycle of yak. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that the modules are enriched into Wnt, EMC-receptor interaction, PI3K-Akt, focal adhesion pathways, and so on. The hub genes, such as FER, ELMO1, PCOLCE, and HOXC13, were screened in different modules. Five hub genes (WNT5A, HOXC13, DLX3, FOXN1, and OVOL1) and part of key lncRNAs were identified for specific expression in skin tissue. Furthermore, immunofluorescence staining and Western blotting results showed that the expression location and abundance of DLX3 and OVOL1 are changed following the process of the HFs cycle, which further demonstrated that these two hub genes may play important roles in HFs development.

Genome-wide association study of fleece traits in Inner Mongolia Cashmere goats

Inner Mongolia Cashmere goat is a well-known local cashmere goat breed in China. It is famous for excellent fleece quality and a significant advantage in cashmere yield compared to other cashmere goat breeds. In this study, a genome-wide association study was used to investigate fiber length, fiber diameter, and cashmere yield of 192 Inner Mongolia Cashmere goats using the Illumina GoatSNP52K Beadchip panel. We discovered that four single nucleotide polymorphisms (SNPs) reached genome-wide significance levels. These SNPs were located in some genes, e.g. FGF12, SEMA3D, EVPL, and SOX5, possibly related to fleece traits in Inner Mongolia Cashmere goat. Gene ontology enrichment analysis revealed that these genes were enriched in several biological pathways that were involved in hair follicle development in cashmere goats. In summary, the identified significant SNPs and genes provide useful information to explore genetic mechanisms underlying the variation in fleece traits and genomic selection of Chinese cashmere goat.

Genome-wide scan for selection signatures reveals novel insights into the adaptive capacity in local North African cattle

Natural-driven selection is supposed to have left detectable signatures on the genome of North African cattle which are often characterized by the fixation of genetic variants associated with traits under selection pressure and/or an outstanding genetic differentiation with other populations at particular loci. Here, we investigate the population genetic structure and we provide a first outline of potential selection signatures in North African cattle using single nucleotide polymorphism genotyping data. After comparing our data to African, European and indicine cattle populations, we identified 36 genomic regions using three extended haplotype homozygosity statistics and 92 outlier markers based on Bayescan test. The 13 outlier windows detected by at least two approaches, harboured genes (e.g. GH1, ACE, ASIC3, HSPH1, MVD, BCL2, HIGD2A, CBFA2T3) that may be involved in physiological adaptations required to cope with environmental stressors that are typical of the North African area such as infectious diseases, extended drought periods, scarce food supply, oxygen scarcity in the mountainous areas and high-intensity solar radiation. Our data also point to candidate genes involved in transcriptional regulation suggesting that regulatory elements had also a prominent role in North African cattle response to environmental constraints. Our study yields novel insights into the unique adaptive capacity in these endangered populations emphasizing the need for the use of whole genome sequence data to gain a better understanding of the underlying molecular mechanisms.

Characterization and functional analysis of Krtap11-1 during hair follicle development in Angora rabbits (Oryctolagus cuniculus)

BACKGROUND

Keratin-associated protein (KAP), the structural protein molecule of hair fibers, plays a key role in determining the physical properties of hair. Studies of Krtap11-1 have focused only on its localization. Functional studies of Krtap11-1 in hair follicle development have so far not been reported.

OBJECTIVE

This study aimed to provide evidence for the role of Krtap11-1 in skin and hair development.

METHODS

Full-length cloning and analysis of Krtap11-1 were conducted to ascertain its function. Overexpression vectors and interference sequences were constructed and transfected into RAB-9 cells. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to investigate the hair follicle developmental stage of Krtap11-1, the expression of different tissues, and the effects on other hair follicle development-related genes.

RESULTS

The full length of cloned Krtap11-1 was 947 bp. Krtap11-1 was confirmed to be a hydrophilic protein localized mostly in mitochondria. The greatest mRNA expression was observed in skin. Using a follicle synchronization model, it was found that Krtap11-1 mRNA expression levels first increased then decreased over the passage of time, principally during hair follicle catagen and telogen. Following the overexpression of Krtap11-1, mRNA expression levels of the WNT-2, KRT17, BMP-2, and TGF-β-1 genes increased, and LEF-1 decreased (P < 0.05), the converse after the corresponding use of si-RNA interference.

CONCLUSIONS

Krtap11-1 exerts a promoting effect. The results provide novel insight into the relationship between hair follicle development and Krtap11-1 gene expression.