Search Results (6)

Natural selection and artificial breeding are crucial methods for developing new animal groups. The Baiyu black goats and Chuanzhong black goats are indigenous goat breeds from distinct ecological regions in Sichuan Province, with dramatically different growth and reproductivity. This study aimed to systematically elucidate the differences in production performance and genetic traits between Baiyu black goats and Chuanzhong black goats. We quantified growth and reproductive attributes for both breeds. Furthermore, we conducted a comprehensive analysis of genetic diversity, population structure, and selection signatures using whole-genome resequencing data. This dataset included 30 individuals from the Baiyu black goat breed, 41 from the Chuanzhong black goat breed, and an additional 59 individuals representing Chengdu grey goats, Tibetan cashmere goats, and Jianchang black goats, totaling 130 individuals across five goat breeds. The comparative analysis of production performance revealed that the weight and body size of Chuanzhong black goats were significantly higher than those of Baiyu black goats (p < 0.01). At the same time, the average kidding rate and kid-weaning survival rate of Chuanzhong black goats were also notably superior to those of Baiyu black goats (p < 0.01). The Baiyu black goats exhibited a more abundant genetic diversity and distinct genetic differences compared to the Chuanzhong black goat, according to an analysis grounded on genomic variation. The Baiyu black goats are more closely related to Tibetan cashmere goats, whereas Chuanzhong black goats share a closer genetic relationship with Chengdu grey goats. Additionally, we employed the π, Fst, and XP-EHH methodologies to identify genes related to immunity (TRIM10, TRIM15, TRIM26, and TRIM5), neurodevelopment (FOXD4L1, PCDHB14, PCDHB4, PCDHB5, PCDHB6, and PCDHB7), reproduction (BTNL2 and GABBR1), body size (NCAPG, IBSP, and MKNK1), and meat quality traits (SUCLG2 and PGM5). These results provide a theoretical basis for further resource conservation and breeding improvement of the Baiyu black goat and Chuanzhong black goat. Full article

The Tibetan cashmere goat is a prolific goat breed in China. In sheep breeds, natural mutations have demonstrated that the transforming growth factor beta (TGF-β) super family ligands, such as growth differentiation factor 9 (GDF9), bone morphogenetic protein 15 (BMP15) and their type I receptor (bone morphogenetic protein receptor (BMPR1B), are essential for ovulation and increasing litter size. In this study, 216 female Tibetan cashmere goats were sampled, and candidate genes with fecundity traits were detected via restriction fragment length polymorphism (RFLP) and sequenced. Four polymorphic loci were found in specific amplification fragments of BMP15 and GDF9. Two SNP sites of the BMP15 gene were discovered, namely G732A and C805G. The G732A mutation did not cause the change in amino acids, and the frequencies of each genotype were 0.695 for the GG type, 0.282 for the GA type and 0.023 for the AA type. The C805G mutation caused amino acids to change from glutamine to glutamate. The genotype frequencies were 0.620 for the CC type, 0.320 for the CG type and 0.320 for the CG type. For the GG type 0.060, the G3 and G4 mutations of the GDF9 gene were all homozygous mutations. Two known SNP sites, C719T and G1189A, were detected in the Tibetan cashmere goat GDF9 gene, of which the C719T mutation caused a change of alanine to valine, with a genotype frequency of 0.944 for the CC type and 0.056 for the CT type, whereas no TT type was found. The G1189A mutation caused valine to become isoleucine, and the frequencies of each genotype were 0.579 for the GG type, 0.305 for the GA type and 0.116 for the AA type; G1, B2, B3, B4, FecX^H, FecX^I, FecX^L, G2, G5, G6, G7, G8, FecG^E, FecTT and FecB mutations were not found in Tibetan cashmere goats. The results of this study provide a data basis for future studies of BMP15, GDF9 and BMPR1B gene mutations in goats. Full article

The Tibetan cashmere goat is a precious breed in China and its cashmere is widely used in clothing and textiles. The genes IGF-1, FGF5, and KAP 1.4 have been shown to be crucial regulators of cashmere growth. In this study, we examined mRNA expression levels of these three genes and detected IGF-1, FGF5, and KAP 1.4 SNP loci in the Tibetan cashmere goat. After amplification and sequence alignment of the genes IGF-1, FGF5, and KAP 1.4 among 206 Tibetan cashmere goats, two new SNP loci were detected in gene KAP 1.4, while no SNP loci were found in amplified fragments of genes IGF-1 and FGF5. The expression levels of gene IGF-1 in Baingoin and Nyima counties were significantly higher than in other counties (p < 0.05). Moreover, the expression level of gene FGF5 in Gêrzê was significantly higher than in Rutog. The expression levels of mRNA in KAP 1.4 showed significant variation among seven counties. There were no significant differences in mRNA expression levels of IGF-1, FGF5, and KAP 1.4 in Tibetan cashmere goats when analysed by sex. The gene IGF-1 was slightly up-regulated in one to five-year-old cashmere goats, except in those that were 4 years old. The mRNA expression levels of FGF5 in one and two-year-old cashmere goats was lower compared with those in three to five-year-old cashmere goats. KAP 1.4 was up-regulated across one to five-year-old cashmere goats. In this study, SNP detection and mRNA expression analysis of IGF-1, FGF5, and KAP 1.4 genes was able to add data to genetic evolutionary analysis. Further studies should be carried out in SNPs to detect other fragments in genes IGF-1 and FGF5, as well as signal pathways and gene functions in protein levels of genes IGF-1, FGF5, and KAP 1.4 in the Tibetan cashmere goat. Full article

High-altitude environments dramatically influenced the genetic evolution of vertebrates. However, little is known about the role of RNA editing on high-altitude adaptation in non-model species. Here, we profiled the RNA editing sites (RESs) of heart, lung, kidney, and longissimus dorsi muscle from Tibetan cashmere goats (TBG, 4500 m) and Inner Mongolia cashmere goats (IMG, 1200 m) to reveal RNA editing-related functions of high-altitude adaptation in goats. We identified 84,132 high-quality RESs that were unevenly distributed across the autosomes in TBG and IMG, and more than half of the 10,842 non-redundant editing sites were clustered. The majority (62.61%) were adenosine-to-inosine (A-to-I) sites, followed by cytidine-to-uridine (C-to-U) sites (19.26%), and 32.5% of them had a significant correlation with the expression of catalytic genes. Moreover, A-to-I and C-to-U RNA editing sites had different flanking sequences, amino acid mutations, and alternative splicing activity. TBG had higher editing levels of A-to-I and C-to-U than IMG in the kidney, whereas a lower level was found in the longissimus dorsi muscle. Furthermore, we identified 29 IMG and 41 TBG population-specific editing sites (pSESs) and 53 population-differential editing sites (pDESs) that were functionally involved in altering RNA splicing or recoding protein products. It is worth noting that 73.3% population-differential, 73.2% TBG-specific, and 80% IMG-specific A-to-I sites were nonsynonymous sites. Moreover, the pSESs and pDESs editing-related genes play critical functions in energy metabolisms such as ATP binding molecular function, translation, and adaptive immune response, which may be linked to goat high-altitude adaptation. Our results provide valuable information for understanding the adaptive evolution of goats and studying plateau-related diseases. Full article

Convergent evolution provides powerful opportunities to investigate the genetic basis of complex traits. The Tibetan antelope (Pantholops hodgsonii) and Siberian ibex (Capra sibirica) belong to different subfamilies in Bovidae, but both have evolved similar superfine cashmere characteristics to meet the cold temperature in plateau environments. The cashmere traits of cashmere goats underwent strong artificial selection, and some traces of domestication also remained in the genome. Hence, we investigated the convergent genomic signatures of cashmere traits between natural and artificial selection. We compared the patterns of convergent molecular evolution between Tibetan antelope and Siberian ibex by testing positively selected genes, rapidly evolving genes and convergent amino acid substitutions. In addition, we analyzed the selected genomic features of cashmere goats under artificial selection using whole-genome resequencing data, and skin transcriptome data of cashmere goats were also used to focus on the genes involved in regulating cashmere traits. We found that molecular convergent events were very rare, but natural and artificial selection genes were convergent enriched in similar functional pathways (e.g., ECM-receptor interaction, focal adhesion, PI3K-Akt signaling pathway) in a variety of gene sets. Type IV collagen family genes (COL4A2, COL4A4, COL4A5, COL6A5, COL6A6) and integrin family genes (ITGA2, ITGA4, ITGA9, ITGB8) may be important candidate genes for cashmere formation and development. Our results provide a comprehensive approach and perspective for exploring cashmere traits and offer a valuable reference for subsequent in-depth research on the molecular mechanisms regulating cashmere development and fineness. Full article

This experiment compared secondary hair follicles (SFs) in Tibetan cashmere goats from two different steppes that were at different altitudes and had different temperatures. Twenty-four 2-year-old goats were studied. Twelve goats were from Rikaze in Tibet which is at an altitude of above 5000 m with an average temperature of 0 °C. The other 12 studied goats were from Huan County of Gansu Province which is around 2000 m above sea level with an average temperature of 9.2 °C. The structural features of SFs were assessed using light microscopy and transmission electron microscopy. The presence of HIF-1a, HIF-2a, HIF-3a, HSP27, and HOXC13 proteins was studied using immunohistochemistry and immunofluorescence. Light and electron microscopy revealed that the SFs of the Tibetan cashmere goats that lived in the Rikaze Steppe were in the proanagen stage in May. However, the SFs of the goats from the lower warmer Huan County were in the anagen stage at the same time. Immunohistochemistry revealed intense immunostaining for HIF-1a protein in the inner root sheath (IRS) and hair shaft (HS); immunostaining against HIF-2a in the outer root sheath (ORS) and IRS; HIF-3a protein immunostaining in the ORS; HSP27 immunostaining in the ORS, IRS, and HS; and HOXC13 immunostaining in the ORS and HS. HIF-1a protein expression in the IRS and HS was higher than the expression in the ORS (p < 0.05) while the expression of HIF-2a protein was higher in the ORS and IRS than the HS (p < 0.05). The expression of HIF-3a protein was higher in the ORS than in the IRS (p < 0.05). Expression of HOXC13 protein was higher in the ORS than in the IRS and HS (p < 0.05). Immunostaining of HIF-1a, HIF-2a, and HSP27 protein was significantly higher in SFs from cashmere goats from Rikaze than in goats from Huan (p < 0.05). In contrast, HOX13 protein immunostaining was significantly higher in cashmere goats from Huan than from Rikaze (p < 0.05). Significant differences were observed in the SFs of cashmere goats from two locations that differ in altitude and temperature. This suggests the differences in the secondary hair follicles could be due to the hypoxia and lower temperatures experienced by the goats in Rikaze. These results are useful in understanding how altitude and temperature influence SF development. Hair produced by the SFs are used for down fiber. Therefore, understanding of the factors that influence SF development will allow the production and harvest of these valuable fibers to be maximized. Full article