Background/Objectives: Research on cashmere goat coat color is crucial for optimizing cashmere goat breeds and increasing their economic value. To identify key genes associated with the formation of cashmere goat coat color and to provide molecular markers for breeding purposes, three healthy, 3-year-old does with similar weights and distinct coat colors—white, black, and light brown—were selected. Methods: Skin samples were collected for transcriptome sequencing, and bioinformatics methods were applied to screen for differentially expressed genes (DEGs) in the skin of cashmere goats with varying coat colors. Real-time fluorescence quantitative PCR (qRT-PCR) and immunofluorescence were subsequently conducted to examine the expression patterns of these DEGs. Results: The results showed that a total of 1153 DEGs were identified across the three groups of cashmere goats. According to GO and KEGG analyses, these DEGs were involved in key biological processes and structures, such as the melanin biosynthetic process (GO:0042438), melanosome membrane (GO:0033162), and melanin biosynthesis from tyrosine (GO:0006583). Employing Cytoscape, a gene interaction network was plotted, highlighting a compact network of DEGs associated with coat color formation. Critical genes identified included TYRP1, TYR, DCT, ASIP, PMEL, LOC102180584, MLANA, TSPAN10, TRPM1, CLDN16, AHCY, LOC106503350, and LOC102175263. qRT-PCR and fluorescence immunohistochemistry further determined that TYRP1, TYR, DCT, and PMEL expression levels were high in black goats (BGs), while ASIP and AHCY expression levels were high in white goats (WGs). The expression levels of these six genes in light brown goats (RGs) were intermediate between those in BGs and WGs. Conclusions: TYRP1, TYR, DCT, and PMEL were believed to play pivotal roles in the formation of black coat color, while ASIP and AHCY regulated the formation of white coat color in cashmere goats.

The cashmere goat ( Capra hircus ) is famous for the fine quality cashmere wool. The cashmere is produced by secondary hair follicle that the growth shows seasonal rhythm. Thus, in this study, the skin of cashmere goat was selected as a model to illustrate the circannual rhythm of skin. The whole length skin transcriptome mixed from selected four months was obtained by PacBio single-molecule long-read sequencing (SMRT) technology. We generated 82,382 high quality non-redundant transcripts belonging to 193,310 genes, including 4,237 novel genes. Other 39 skin transcriptomes sampled from Dec. 2014 to Dec. 2015 were sequenced by Illumina Hi-Seq2500, we found 980 genes were differentially expressed. Of these genes, 403 seasonal rhythm genes (SRGs) were expressed and exhibited a seasonal pattern in skin. The results also showed that miRNAs were differentially expressed as the daylight length changed throughout a year. Some SRG genes related to the hormone secretion and eyes morphogenesis were enriched in skin. These genes gradually increased their expression level under short light, reached the peak near the summer solstice, and then began to decline. We found that the expression of Dio1 gene may be affected by the photoperiod that induces transformation from the inactive T4 to active thyroid hormone T3 in the skin and led to the difference between the skin circannual rhythm and the core circannual rhythm. Furthermore, the skin expressed eye morphogenesis-related genes and miRNAs, which suggested some cells in the skin could have the potential of light sensitivity. These results revealed that SRGs could regulate the downstream gene expression and physiological process in the skin to adapt to the season change.

During the wintering period characterized by feed scarcity, animals activate the sympathetic nervous system (SNS)-β-adrenergic receptor (βAR)-AMP-activated protein kinase (AMPK)/peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) signaling pathway in their bodies. This activation increases the transcriptional activity of forkhead box O1 (FOXO1) transcription factor and pyruvate dehydrogenase kinase 4 (PDK4), leading to the upregulation of gluconeogenesis-limiting genes phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase). Additionally, it enhances the functions of carnitine palmitoyltransferase 1 (CPT1), uncoupling protein 1 (UCP1), cluster of differentiation 36 (CD36), and fatty acid transport protein (FATP). This promotes promote intermuscular fat oxidation and the production of gluconeogenesis precursor glycerol, thereby enhancing animal skeletal muscle gluconeogenesis to maintain animal energy homeostasis and life activities under low temperature and starvation conditions. This article describes the effects of overwintering starvation stress on the AMPK/PGC-1α signaling pathway and its molecular mechanism in animal skeletal muscle gluconeogenesis. The aim to provide a theoretical basis for optimizing sustainable breeding strategies and improving animal production performance in alpine regions.

BackgroundThe cashmere goat (Capra hircus) is famous for the fine quality cashmere wool. The cashmere is produced by secondary hair follicle that shows seasonal rhythm in growth. Thus, in this study, the skin of cashmere goat was selected as a model to illustrate the circannual rhythm of skin. ResultsThe skin whole length transcriptome obtained by PacBio single-molecule long-read sequencing (SMRT) technology were mixed from four selected months. The transcriptome yielded 82,382 high quality non-redundant transcripts belonging to 193,310 genes, including 4,237 novel genes. Other 39 skin transcriptomes sequenced by Illumina Hi-Seq2500 were sampled from Dec. 2014 to Dec. 2015, from which we found 980 genes were differentially expressed. Of these genes, 403 seasonal rhythm genes (SRGs) were expressed and exhibited a seasonal pattern in skin. Some SRG genes related to the hormone secretion and eyes morphogenesis were enriched in skin. These SRG genes gradually increased their expression level under short light, reached the peak near the summer solstice, and then began to decline. We found that the expression of Dio1 gene may be affected by the photoperiod that induces transformation from the inactive T4 to active thyroid hormone T3 in the skin and led to the difference between the skin circannual rhythm and the core circannual rhythm. The results also showed that miRNAs were differentially expressed as the daylight length changed throughout a year. Furthermore, the skin expressed eye morphogenesis-related genes and miRNAs, which suggested some cells in the skin could have the potential of light sensitivity. ConclusionTaking together, these results revealed that SRGs could regulate the downstream gene expression and physiological process in the skin to adapt to the season change. We provided a hypothesis to describe how goat skin makes the own rhythm and gets the clue from the environment factor.