Traits In Goats Research Articles

Effect of GH gene polymorphism on growth traits in goats of Meghalaya’s subtropical hilly region

Effect of GH gene polymorphism on growth traits in goats of Meghalaya’s subtropical hilly region

Comparative ultrastructural and transcriptomic profile analysis of skin tissues from indigenous, improved meat, and dairy goat breeds.

High-quality goatskins are valuable byproducts usually produced by indigenous goat breeds with poorer production performance in Asia and Africa. However, the genetic and molecular mechanisms underpinning goatskin's biomechanical properties (e.g., tensile strength) remain elusive. Mechanistic exploration of these traits could greatly aid the genetic improvement and genetic resource conservation of native breeds in these regions. To fulfill this purpose, we collected skin tissues from three goat breeds: Huai goat (HG), a Chinese native variety producing high-quality goatskins; Yudong meat goat (YDMG), a crossbreed of HG and Boer goat; Henan dairy goat (HNDG), a dairy goat breed. Scanning electronic microscopy analysis of skin tissues found that the collagen fiber diameters, collagen fibril diameters, and crimps significantly differed among the three goat breeds; however, collagen fibril diameters are similar in HG and HNDG. A sum of 230, 775, and 86 differentially expressed genes (DEGs) were identified from YDMG versus HNDG, HG versus HNDG, and YDMG versus HG, respectively. Functional enrichment analysis suggested that signaling pathways involved in fatty acid, retinol, steroid metabolisms, and GO items related to the physical properties of the skin (e.g., collagen-containing extracellular matrix) are significantly overrepresented in DEGs identified from meat versus dairy goats. Furthermore, 106 DEGs (e.g., COL1A1, COL1A2, and SPARC) showed specific expression patterns in HG and YDMG versus HNDG. Items about biophysical features of skin (e.g., extracellular matrix organization and ECM proteoglycans) are markedly enriched. Protein-protein interaction analysis suggested that two growth factors (IGF1 and PDGFD) are latent collagen and other ECM protein expression modulators. Ultrastructural analysis of goat skin tissues suggested that collagen fibril diameter is not a major factor affecting goatskin quality. Transcriptomic profiles unveiled core genes and associated biological processes potentially involved in regulating goatskin quality. These discoveries shined new light on deeper understanding the mechanisms of hide-related traits in goat and other livestock.

Effects of preslaughter handling approach and aging on carcass and meat quality attributes in goats

This study aimed to assess the impact of preslaughter handling method and aging on carcass and meat quality traits in goats. Twenty-seven male goats of Ardi breed were assigned into three treatment groups viz., the control (C), ear pulling (EP), and hind-leg pulling (HP). The carcasses were stored for post-mortem aging periods of 1, 7, and 14 days. On day 0 and the respective aging days, samples of the Longissimus thoracic et lumborum (LTL) muscles were collected and examined for various meat quality parameters. The preslaughter handling of goats significantly increase the total bacterial count, total Enterobacteriaceae count, and total Clostridium count. It also had a significant effect on the pH of LTL muscle during aging. A significantly lower values for pH were recorded in the treatment groups (EP and HP) as compared to the pH of the C group on day 1 of aging. Notably, both treatment groups were found to increase the shear force, hardness, and chewiness of the meat, ultimately compromising its quality. The proper treatment of meat animals, especially goats, is crucial for enhancing carcass and meat quality. Careful preslaughter handling practices by avoiding ear and hind-leg pulling can minimize negative impacts on the final product. Therefore, the significance of conducting this study lies in its potential to enhance animal welfare, improve meat quality, boost economic benefits for producers, and foster consumer confidence in meat products.

The impact of LEP gene polymorphisms located at exon 2 (LEP-HinfI) and intron 2 (LEP-Sau3AI) on growth and reproductive traits in Saanen goats

Abstract. Leptin (LEP), alternatively recognized as the obesity gene, influences food consumption, energy balance, and lipid metabolism. Additionally, it plays a crucial role in energy metabolism, and variations in the LEP gene have been studied extensively among various livestock species. These investigations have unveiled correlations with traits such as meat quality, milk yield and composition, and growth characteristics. Nevertheless, the existing knowledge regarding its correlation with growth and reproductive traits in goats is comparatively limited, particularly when juxtaposed with studies of cattle. Hence, the objective of the current study was to investigate the relationship between polymorphisms in the intron 2 (Sau3AI) and exon 2 (HinfI) regions of the LEP gene and growth and reproductive traits in Saanen goats. The study comprised 185 Saanen goats in total. The PCR-RFLP (polymerase chain reaction restriction fragment length polymorphism) technique was employed to genotype these polymorphisms. Population genetic analysis included the number of effective alleles, heterozygosity, polymorphism information content, and compatibility with the Hardy–Weinberg equilibrium. The general linear model procedure's least-squares methods were used for the statistical analysis. The SNP (single-nucleotide polymorphism) located in exon 2 (LEP-HinfI) was monomorphic. Remarkably, the SNP located in intron 2 (LEP-Sau3AI) was associated with birth weight (p<0.05) and average daily weight gain (p<0.05). In this context, the AA genotype demonstrated higher birth weight and daily live weight gain means compared to other genotypes. No significant differences were observed in litter size, total weight gain, or morphometric measurements. The caprine LEP-Sau3AI polymorphism situated within intron 2 proved influential in traits critical for the profitability and sustainability of goat breeding. The findings of this study provide novel and valuable information for future research on the LEP gene in goats.

Ovarian multi-omics analysis reveals key rate-limiting enzymes FASN, SCD5, FADS1, 3BHSD, and STAR as potential targets for regulating kidding traits in goats

The kidding traits of goats are an important index of production. However, the molecular regulatory mechanisms of kidding traits in goats have not been fully elucidated. This study aimed to investigate the molecular regulatory network of kidding traits in goats. Multi-omics revealed the enrichment of 10 signaling pathways, with fatty acid biosynthesis, biosynthesis of unsaturated fatty acids, and steroid hormone biosynthesis pathways being closely related to reproduction. Interestingly, the key rate-limiting enzymes, fatty acid synthase (FASN), stearoyl-CoA desaturase 5 (SCD5), fatty acid desaturase 1 (FADS1), 3β-hydroxysteroid dehydrogenase/isomerase (3BHSD), and steroidogenic acute regulatory protein (STAR) enriched in these pathways regulate changes in reproduction-related metabolites. In interference experiments, it was observed that suppressing these key rate-limiting enzymes inhibited the expression of CYP19A1, ESR2, and FSHR. Furthermore, interference inhibited granulosa cell proliferation, caused cell cycle arrest, and promoted apoptosis. Thus, these results suggest that the specific markers of nanny goats with multiple kids are the key rate-limiting enzymes FASN, SCD5, FADS1, 3BHSD, and STAR. These findings may greatly enhance the understanding of regulatory mechanisms that govern goat parturition.

Genetic improvement and conservation of goats in tropic

Goats indeed have a significant historical and contemporary importance in human civilization, particularly in the realm of agriculture and food production. Their adaptability and widespread distribution have made them crucial for various societies across the world. Goats have played a central role in the Neolithic agricultural revolution, aiding in the spread of human civilization globally. Their adaptability allowed them to thrive in diverse environments, contributing to the sustenance and expansion of human settlements. Goats are highly adaptable and are found in a wide range of geographical regions. Their presence spans across continents, from tropical to temperate climates, showcasing their ability to thrive in various environmental conditions. There is diversity in the production performance of goats based on the region of the world and the specific breeds. Genetic improvement programs aim to enhance economically important traits such as milk production, growth rates and fiber production, thereby increasing productivity and income for goat farmers. Understanding the genetic parameters such as heritabilities and repeatabilities for various traits is crucial for designing effective breeding programs. These parameters provide insights into the genetic potential of goats for traits like milk production, growth and fiber quality. Heritability estimates for reproductive traits, body weight, daily gain and direct and maternal heritability are important for implementing selective breeding strategies aimed at improving overall productivity and efficiency in goat farming. Genetic improvement programs have been implemented in tropical environments to enhance milk production traits in goats. Genetic improvements have also targeted fiber production in goats, with a focus on traits such as grease fleece weight and average fiber diameter. These efforts aim to enhance the quality and quantity of fiber produced by goats for various commercial purposes. Despite the importance of conserving goat breeds with unique characteristics, planned conservation programs in tropical regions are often neglected. It’s emphasized that preserving indigenous goat breeds in their native habitats is essential for maintaining genetic diversity and ensuring future resilience in goat farming.

Relationship between Indel Variants within the JAK2 Gene and Growth Traits in Goats.

Janus kinase 2 (JAK2) plays a critical role in myoblast proliferation and fat deposition in animals. Our previous RNA-Seq analyses identified a close association between the JAK2 gene and muscle development. To date, research delving into the relationship between the JAK2 gene and growth traits has been sparse. In this study, we sought to investigate the relationship between novel mutations within the JAK2 gene and goat growth traits. Herein, two novel InDel (Insertion/Deletion) polymorphisms within the JAK2 gene were detected in 548 goats, and only two genotypes were designated as ID (Insertion/Deletion) and DD (Deletion/Deletion). The results indicate that the two InDels, the del19008 locus in intron 2 and del72416 InDel in intron 6, showed significant associations with growth traits (p < 0.05). Compared to Nubian and Jianzhou Daer goats, the del72416 locus displayed a more pronounced effect in the Fuqing breed group. In the Nubian breed (NB) group, both InDels showed a marked influence on body height (BH). There were strong linkages observed for these two InDels between the Fuqing (FQ) and Jianzhou (JZ) populations. The DD-ID diplotype was associated with inferior growth traits in chest width (ChW) and cannon circumference (CaC) in the FQ goats compared to the other diplotypes. In the NB population, the DD-DD diplotype exhibited a marked negative impact on BH and HuWI (hucklebone width index), in contrast to the other diplotypes. In summary, our findings suggest that the two InDel polymorphisms within the JAK2 gene could serve as valuable molecular markers for enhancing goat growth traits in breeding programs.

The novel candidate gene Grb10 regulates the growth performance of Guizhou white goats

Growth factor receptor binding protein 10 (Grb10) regulates muscle growth but its function in goats is not well studied. This study examined the relationship between Grb10 gene polymorphism and growth traits in Guizhou white goats. Further, the effect of promoter polymorphism on Grb10 transcription was analyzed via a dual-luciferase assay. Quantitative reverse transcription-polymerase chain reaction analysis showed that the expression level of the Grb10 gene was the highest in the longissimus dorsi muscle (P < 0.01) and the lowest in the spleen. Moreover, sequencing results showed that the Grb10 gene had five single nucleotide polymorphisms. The association analysis showed that g.–246 C > T, g.72323 T > C, and g.178634 A > G loci were significantly associated with growth traits (P < 0.05). Linkage disequilibrium analysis of each locus showed that g.72323 T > C and g.72814 T > A loci had the strongest linkage (r2 = 0.482, D' = 0.73). Furthermore, according to an analysis conducted using TFDB4 software, it was predicted that a mutation in the promoter region of the g.–246 C > T locus resulted in the absence of four transcriptional regulatory factors. The results of dual-luciferase reporter assay further demonstrated that mutation of the g.–246 C > T locus reduced the transcriptional activity of the promoter region of the Grb10 gene. These findings suggest that Grb10 gene polymorphism could affect growth traits in goats.

Competing Endogenous RNAs (ceRNAs) and Application of Their Regulatory Networks in Complex Traits and Diseases of Ruminants

This manuscript summarizes information on the diverse range of RNA molecules and their role as competing endogenous RNAs (ceRNAs). Moreover, it provides an overview of ceRNA regulatory networks and their applications in ruminant biology. Knowledge of co-expression networks has increased with microarrays, RNA-seq, and scRNA-seq characterizing molecular mediators across various biological scales, using sequences from numerous blood and tissue samples. By synthesizing existing knowledge, this study summarizes interactions between coding and non-coding RNAs through microRNA response elements (MREs), elucidating large-scale regulatory networks throughout the transcriptome that influence the expression and activities of various ceRNAs. Identification of non-coding RNAs with important regulatory functions will revolutionize understanding of RNA biology, shifting from an mRNA-centric model to a complex network of RNA crosstalk. The ceRNA networks offer a more comprehensive and arguably more realistic perspective compared to protein–protein interaction (PPI) networks and weighted gene co-expression networks (WGCN). These ceRNA regulatory networks can describe potential molecular regulatory mechanisms related to functional and economically important traits in ruminants, plus contribute to disease and pathology research, by elucidating pathogenesis and potential drug effects in disease and cancer models. Furthermore, they can provide insights into farm animal biology, e.g., reproductive traits in goats and sheep, regulation of fat metabolism in beef cattle, heat stress responses, and lactation regulation in dairy cattle, fertility and muscle characteristics in buffalo, and resistance to high-salt and water-deprivation conditions in camels. In conclusion, ceRNA and associated regulatory networks should promote a new understanding of molecular mechanisms and identify candidate genes and metabolic-signaling pathways in ruminants.

An Identification of Functional Genetic Variants in B4GALNT2 Gene and Their Association with Growth Traits in Goats.

β-1,4-N-acetylgalactosamine transferase 2 (B4GALNT2) is a vital candidate gene that affects the growth traits in sheep. However, whether it has the same function in goats remains to be investigated further. This study selected 348 Nanjiang Yellow goats, screened all exons, and conserved non-coding regions of the B4GALNT2 gene for single-nucleotide polymorphisms (SNPs). Our results revealed the presence of a synonymous mutation, rs672215506, within the exon of the B4GALNT2 gene in the Nanjiang Yellow goat population. The mutation resulted in a decrease in the mRNA stability of the B4GALNT2 gene. The results of SNP detection of the conserved non-coding region of the B4GALNT2 gene showed five potential regulatory SNPs in the Nanjiang Yellow goat population. Except for rs66095343, the ~500 bp fragments of the other four SNPs (rs649127714, rs649573228, rs652899012, and rs639183528) significantly increased the luciferase activity both in goat skeletal muscle satellite cells (MuSCs) and 293T cells. The genetic diversity indexes indicated low or intermediate levels for all six SNPs analyzed, and the genotype frequencies were in Hardy-Weinberg equilibrium. Association analysis showed that rs660965343, rs649127714, and rs649573228 significantly correlate with growth traits in the later stage of growth and development of Nanjiang Yellow goats. The haplotype combinations of H2H3 and H2H2 had higher body weight and greater body size. Moreover, H2H2 haplotype combinations significantly correlated with the litter size of the Nanjiang Yellow goats. The results of our study demonstrate the potential role of the B4GALNT2 gene as a functional genetic marker in the breeding programs of Nanjiang Yellow goats.

Bone Morphogenetic Protein 4 Gene Polymorphism as a Potential Biomarker of Reproductive Traits in Goat

Bone Morphogenetic Protein 4 Gene Polymorphism as a Potential Biomarker of Reproductive Traits in Goat

Detection of MC4R Gene Genotypes and A Relationship SNP13 to Productive and Reproductive Performance in Iraqi Local Goats and Shami Goats

The study was conducted at the Ruminant Research Station of the Agricultural Research Department / Ministry of Agriculture, for the period from 1/12/2021 - 30/10/2022, the current study revealed the relationship between the genotypes of the MC4R gene and its relationship with the productive and reproductive traits in goats. Using 50 goats under the same breeding conditions (25 Syrian goats and 25 Iraqi goats). The results showed that the 13SNP mutation in the MC4R gene in the mothers of Shami goats showed a significant relationship, where the genotype GA was significantly (P≤0.05) superior to the genotype GG in this strain for the characteristic of the daily milk production rate (kg), as well as for the characteristic of the length of the peak of production (day), as well as the characteristic of the percentage of protein in milk (%), and the characteristic of the weight gain of the mother between birth and weaning, with an average of (541.07, 426.76), (43.01, 34.17), (3.16, 3.01), respectively. Conclusion it is the Mutations in genetic and environmental factors play an essential role in livestock animals in terms of productive and economic traits. Thus, the effects of mutations in the MC4R gene were found to have an impact on some productive and reproductive traits in goats.

A novel 22-bp InDel within FGF7 gene is significantly associated with growth traits in goat

Fibroblast growth factor 7 (FGF7) is involved in lipid metabolism, which is considered as a candidate gene with close relation with muscle development by eGWAs and RNA-Seq analyses. To date, limited research has been conducted on the relationship between FGF7 gene and growth traits. The main objective of this work was to further investigate the association between novel InDel within FGF7 gene and growth traits in goat. Herein, FGF7 mRNA expression levels were investigated in various Fuqing goat tissues. We found that FGF7 gene was expressed in six adult goat tissues with the highest mRNA levels in adipose tissue. This result suggested that FGF7 gene might play a critical role in fat deposition. We also detected potential polymorphisms in Fuqing, Nubian and Jianyang Daer breeds. A 22-bp InDel polymorphism in FGF7 gene was detected in 396 goats and the three genotypes were designated as II, ID, and DD. Correlation analysis revealed that InDel polymorphism was significantly associated with growth traits (P < 0.05). Goats with genotypes ID and/or II had superior growth traits compared to those with genotype DD. In summary, our findings suggested that the 22-bp InDel within FGF7 gene could act as a molecular marker to improve the growth traits of goats in breeding programs.

InDel and CNV within the AKAP13 Gene Revealing Strong Associations with Growth Traits in Goat.

A-kinase-anchoring protein 13 (AKAP13) is a member of the AKAP protein family that has been found to be associated with bone formation. Thus, we investigated the AKAP13 gene as a potential candidate gene for molecular-marker-assisted selection (MAS) in breeding. Our aim was to explore genetic variations (InDel and CNV) within the AKAP13 gene of Shaanbei white cashmere (SBWC) goats and analyze their relationship with growth traits. Ultimately, we identified three InDel loci (16-bp deletion, 15-bp insertion, and 25-bp deletion) and three CNVs, and the 16-bp and 15-bp loci were significantly associated with goat body length (p < 0.05). Both the 16-bp deletion variant and the 15-bp insertion variant facilitated an increase in body length in goats. In addition to this, there was a certain superposition effect between 16-bp and 15-bp loci, although there was no linkage. Additionally, the CNV1 locus was significantly correlated with body height and body length of goats (p < 0.05), and CNV2 was significantly correlated with chest depth, chest circumference, and cannon circumference of goats (p < 0.05). Individuals with gain type showed excellent growth performance. In conclusion, the InDel and CNV loci that we have identified could possibly serve as effective molecular markers in goat breeding, which is very essential for improving efficiency and success of breeding. Moreover, our findings provide a new avenue for further research into the function of the AKAP13 gene.

Goat Pleomorphic Adenoma Gene 1 (PLAG1): mRNA Expression, CNV Detection and Associations with Growth Traits.

The pleomorphic adenoma gene 1 (PLAG1) gene, as the major gene responsible for growth, plays a vital role in myogenesis. Meanwhile, the relationship between copy number variation (CNV) of this gene and growth traits in goats remains unclear. Therefore, this study investigated four aspects: bioinformatics analysis, mRNA expression (n = 6), CNV detection (n = 224), and association analysis. The findings indicated that the gene had a large number of conserved motifs, and the gene expression level was higher in fetal goats than in adult goats. Three CNV loci were selected from the database, among which CNV1 was located in the bidirectional promoter region and was associated with goat growth traits. CNV analysis showed that CNV2 and CNV3 of the PLAG1 gene were associated with growth traits such as body weight, heart girth, height at hip cross, and hip width (p < 0.05), with CNV1 loss genotype being the superior genotype, and CNV2 and CNV3 median and gain genotypes of being superior genotypes. This finding further confirms that the PLAG1 gene is the dominant gene for growth traits, which will serve as theoretical guidance for goat breeding.

Expression profile and association of ghrelin gene polymorphism with growth and litter traits in Indian goat breeds

Ghrelin (GHRL) is a 28 amino acid bioactive peptide influencing growth hormone secretion, regulation of energy homeostasis and appetite stimulation. The present investigation was undertaken to study the expression profile of the caprine ghrelin gene and to identify single nucleotide variations in caprine ghrelin gene to evaluate its association with production traits. Tissue samples of abomasum, lung, liver, spleen, fallopian tube and ovary were collected from six Malabari and Attappady Black adult goats to study the ghrelin gene expression pattern. Quantitative Real-Time PCR was used to find out the relative expression of ghrelin in various tissues. It was observed that there was a higher expression of ghrelin in the abomasal (3.67) tissues and the least expression in the liver (0.19) tissues. Significantly higher level of expression was noticed in Attappady Black than Malabari goats. Highly significant (p < 0.01) 4.07 fold upregulation was noticed in the ovary compared to the lung (3.85) and abomasum (3.80). A total of 176 Malabari and Attappady Black adult goats were screened for polymorphism using PCR-SSCP. Representative samples from different band patterns were sequenced. Two SNPs at the 9th position (C→A transversion) and at the 38th position (G→T transversion) in exon 4 and two SNPs at the 45th position (C→T transition) and 89th position (C→T transition) in intron 4 were identified. A significant association was observed between body measurement traits and the identified single nucleotide polymorphisms. The AB genotype demonstrated superior values over the AA genotype in body length and height for exon 4, while for intron 4 AA genotype was superior to the AB genotype. The AB genotype demonstrated higher values over the AA genotype for chest girth, CCI and TI. However, no association was found between body weight and litter size. The ghrelin gene may be used in marker-assisted selection for improving conformation traits in goats.

New insight into copy number variations of goat SMAD2 gene and their associations with litter size and semen quality

Copy number variations (CNV) contribute significantly to genetic variations. Numerous studies have shown that CNV affects phenotypic traits in livestock. The SMAD family member 2 (SMAD2) is a leading candidate gene in reproduction and has a crucial effect on litter size. Additionally, SMAD2 is also required for male reproduction and influences male germ cell development. However, there are no reports on investigating the effect of CNVs in the SMAD2 gene on reproductive traits in goat. Therefore, the goal of this study was to explore associations between CNV of the SMAD2 gene and litter size and semen quality in Shaanbei white cashmere (SBWC) goats. In this study, two CNVs within the SMAD2 were identified in 352 SBWC goats (50 males and 302 females). The association analysis revealed that only CNV2 was significantly associated with female goat first-born litter size (P = 3.59 × 10−4), male semen concentration (P < 0.01), ejaculation volume, live sperm count, and sperm deformity rate (P < 0.05). In terms of phenotypic performance, the individuals with loss genotypes outperformed those with other genotypes. CNV1 and CNV2 genotype combinations containing their dominant genotypes were also associated with goat litter size (P = 1.7 × 10−5), but no differences in semen quality were found. In summary, CNV2 of the SMAD2 gene is useful for molecular marker-assisted selection breeding, as it is associated with essential goat reproductive traits.

Univariate and multivariate genome-wide association studies for hematological traits in Murciano-Granadina goats.

Hematological traits are important indicators of health status, and they are frequently used as criteria for clinical diagnosis. In humans, the genomic architecture of blood traits has been investigated in depth and thousands of associations with genetic variants have been found. In contrast, the association between marker genotypes and the variation of hematological traits has not been investigated in goats yet. Herewith, we have recorded 12 hematological parameters in 882 Murciano-Granadina goats that were also genotyped with the Goat SNP50 BeadChip (Illumina). Performance of a univariate genome-wide association study (GWAS) made it possible to detect one genomic region on goat chromosome (CHI) 21 (19.2-19.5 Mb) associated, at the genome-wide level of significance, with 4 red blood cell traits. The three markers displaying the highest significances were rs268272996 (CHI21: 19225290 bp), rs268273004 (CHI21: 19565629 bp) and rs268239059 (CHI13: 9615190 bp). Consistently, a multivariate GWAS indicated that the rs268273004 marker on chromosome 21 is associated with seven blood cell traits. Interestingly, this marker maps close to the FA Complementation Group I (FANCI) gene (CHI21: 20021947-20077025 bp), which is functionally related to Fanconi anemia, a syndrome characterized by bone marrow failure, aplastic anemia, and congenital disorders. We have also uncovered additional chromosome-wide significant associations between genetic markers and erythrocyte and leukocyte traits in the univariate GWAS. These findings evidence that the phenotypic variation of hematological traits in goats is regulated, at least to some extent, by polygenic determinants distributed in multiple chromosomes.

Whole-genome selective scans detect genes associated with important phenotypic traits in goat (Capra hircus).

Goats with diverse economic phenotypic traits play an important role in animal husbandry. However, the genetic mechanisms underlying complex phenotypic traits are unclear in goats. Genomic studies of variations provided a lens to identify functional genes. In this study, we focused on the worldwide goat breeds with outstanding traits and used whole-genome resequencing data in 361 samples from 68 breeds to detect genomic selection sweep regions. We identified 210-531 genomic regions with six phenotypic traits, respectively. Further gene annotation analysis revealed 332, 203, 164, 300, 205, and 145 candidate genes corresponding with dairy, wool, high prolificacy, poll, big ear, and white coat color traits. Some of these genes have been reported previously (e.g., KIT, KITLG, NBEA, RELL1, AHCY, and EDNRA), while we also discovered novel genes, such as STIM1, NRXN1, LEP, that may be associated with agronomic traits like poll and big ear morphology. Our study found a set of new genetic markers for genetic improvement in goats and provided novel insights into the genetic mechanisms of complex traits.

Association analysis of polymorphisms at GLRB, GRIA2, and GASK1B genes with reproductive traits in Dazu Black Goats

Reproductive traits are essential economic traits in goats. This study aimed to analyze the relationship between single nucleotide polymorphisms (SNPs) within the genes of GLRB, GRIA2, and GASK1B, and reproductive traits (kidding traits and placental traits) in goats. We used the resequencing data of 150 Dazu Black Goats to perform correlation analysis with the average litter size. We screened thirteen SNPs loci in introns and then used the Sanger method to genotype the remaining 150 Dazu Black Goats. The results showed that a total of six SNPs were screened. Three SNPs related to litter size and live litter size (g.28985790T > G, g.28986352A > G, and g.28987976A > G); one SNP related to total cotyledon area (g.29203243G > A); two SNPs related to placental efficiency (g.30189055G > A and g.30193974C > T); one SNP associated with cotyledon support efficiency (g.30193974C > T). The qPCR results showed that GLRB, GRIA2, and GASK1B were all highly expressed in the udder, kidney, uterus, and ovary. It indicated that these three candidate genes might affect the reproductive traits, which could be used as candidate markers for reproductive traits in Dazu Black Goats. Moreover, association studies on a large scale are still needed to figure out what effect these SNPs have on reproductive traits.