Gao Gong

This study aimed to elucidate the characteristics of protein changes and their relationship with physicochemical properties during the quality deterioration of refrigerated Northern Pike (Esox lucius). We employed tandem mass tag (TMT)-based quantitative proteomics, combined with physicochemical indicators, including surface hydrophobicity, carbonyl content, sulfhydryl content, and myofibrillar fragmentation index (MFI), to systematically analyze protein alterations during cold storage. The results showed that with prolonged cold storage, the surface hydrophobicity, carbonyl content, and MFI of Northern Pike samples exhibited an increasing trend, whereas the sulfhydryl content decreased. Proteomic analysis identified a total of 563 differentially expressed proteins (DEPs) between fresh and cold-stored states, of which 293 were upregulated and 270 were downregulated. Furthermore, by integrating COG/KOG functional classification, subcellular localization, and GO enrichment analysis, the functional characteristics of the DEPs and their potential involvement in biological processes were systematically characterized. Correlation analysis revealed that six DEPs were significantly correlated with the changes in physicochemical indices of Northern Pike during cold storage, namely fructose-bisphosphate aldolase encoded by ALDOA, Nesh-SH3 domain-target protein, keratin, neurofilament heavy polypeptide, serine/arginine repetitive matrix protein 2-like, and asymmetrical bis(5′-nucleosidyl) tetraphosphatase. By integrating analyses of differentially abundant proteins and protein oxidation, this study suggests potential molecular mechanisms potentially responsible for quality loss in northern pike under chilled storage, offering a theoretical foundation for its preservation and quality assessment.

The cashmere fibers produced by the secondary hair follicles of cashmere goats are precious textile raw materials. The secondary hair follicles exhibit a distinct annual cyclical pattern, comprising anagen, catagen, and telogen phases. Although a large amount of skin transcriptome data is currently available for cashmere goats, this study aims to systematically investigate the regulatory factors controlling the cyclical dynamics of secondary hair follicles through re-analysis of these data. Skin transcriptome data of Inner Mongolian cashmere goats were downloaded from the Sequence Read Archive (SRA) database. Bioinformatics analyses, including quality control, read mapping, quantification, differential expression analysis, Gene Ontology (GO) enrichment analysis, and KEGG pathway analysis, were performed to identify key regulatory genes governing the secondary hair follicle cycle. The results revealed a total of 1232 differentially expressed genes (DEGs) from comparisons across different phases. KEGG pathway analysis identified three signaling pathways associated with cashmere development: the cAMP signaling pathway (chx04024), the relaxin signaling pathway (chx04926), and the estrogen signaling pathway (chx04915). GO analysis yielded 335 terms, of which 236 were statistically significant (P-adj < 0.05). The DEGs were predominantly involved in biological processes such as regulation of transcription by RNA polymerase II, proteolysis, and positive regulation of transcription by RNA polymerase II. Significantly enriched cellular components included the plasma membrane, membrane, and extracellular space, and molecular functions were mainly related to protein binding, identical protein binding, and DNA-binding transcription factor activity, RNA polymerase II-specific. Based on their expression patterns, five key genes were selected: KRT25, KRT39, MAPK12, SPP1, and TCHHL1. These genes displayed significantly distinct expression profiles across the hair follicle cycle. TCHHL1 exhibited the highest expression in anagen, intermediate expression in catagen, and the lowest expression in telogen, with significant differences among all three phases. MAPK12 was specifically upregulated in telogen and was significantly more highly expressed than in both anagen and catagen. SPP1 showed high expression in anagen and catagen but extremely low expression in telogen. KRT39 displayed significantly higher expression in both anagen and catagen compared to telogen. KRT25 reached its highest expression in catagen, which was significantly different from that in telogen, while its expression in anagen showed no significant difference from either telogen or catagen. This study characterized the regulatory genes of the secondary hair follicle cycle in cashmere goats at the transcriptional level and analyzed the association between their expression patterns and cycle regulation.

Background: Dietary crude protein (CP) acts as a key nutritional factor that affects the growth performance and liver metabolism of fattening Hu sheep, with metabolizable energy (ME) representing a major confounding factor in CP-related responses. To isolate the specific effects of CP on liver metabolism and minimize energy–protein interactions, we standardized dietary ME at 9.4 MJ/kg dry matter. Methods: We then established three isoenergetic CP concentrations: 11.07%, 13.07%, and 15.11%. A total of ninety 4-month-old male Hu sheep (with an initial body weight of 27.09 ± 1.83 kg) were allocated at random to three dietary treatment groups, each containing 30 animals distributed across three replicate pens, and fed pelleted total mixed rations (PTMRs) for 75 days under pen conditions in southern Xinjiang. Exploratory combined transcriptomic and metabolomic profiling of liver tissue was conducted to characterize how graded CP levels modulate growth traits and hepatic metabolic pathways, thereby identifying the appropriate dietary CP level for efficient and sustainable fattening of Hu sheep in this region. Result: Results indicated that animals fed the 15.11% CP diet showed a significantly higher average daily gain (ADG) and cumulative weight gain compared with those fed 11.07% or 13.07% CP (p < 0.05). Exploratory multi-omics enrichment analysis demonstrated significant overrepresentation (p < 0.05) of differentially expressed genes and metabolites in key biological pathways—including bile secretion, AMP-activated protein kinase (AMPK) signaling, steroid biosynthesis, peroxisome proliferator-activated receptor (PPAR) signaling, and oxidative stress-related and oxidative phosphorylation. Correlation analyses characterized two hub genes—ATP6AP1 and LOC101119853—that were significantly and negatively correlated with ADG (p < 0.05), whereas two metabolites—calcidiol and ADP—displayed significant positive relationships with ADG (p < 0.05). Pathway-level comparisons further demonstrated that both the 13.07% vs. 15.11% CP and the 11.07% vs. 15.11% CP contrasts yielded significant enrichment in AMPK signaling and steroid biosynthesis. Notably, calcidiol and ADP both declined numerically in the 13.07% vs. 15.11% CP comparison, whereas only ADP reached statistical significance in the 11.07% vs. 15.11% CP contrast. Conclusions: Collectively, under an ME level of 9.4 MJ/kg, a dietary CP concentration of 15.11% contributes to favorable growth of 4-month-old fattening Hu sheep housed in pens in southern Xinjiang. This level is associated with improved growth performance and coordinated regulation of central hepatic regulatory networks—particularly those involved in energy homeostasis and steroidogenesis—thereby supporting metabolic stability without compromising animal health or production efficiency. These findings provide a preliminary molecular basis for precision protein nutrition in Hu sheep feeding systems and offer translational insights for optimizing ruminant nutrition under arid and semi-arid environmental constraints. All correlations indicate potential associations, not causal relationships.

As a dual-purpose (meat and fat) coarse-wool sheep breed in Xinjiang, the Pishan Red sheep exhibits year-round estrus and excellent reproductive performance. The aim of this study was to systematically estimate the genetic parameters of growth traits in Pishan Red sheep at each stage from 0 to 12 months of age, and to provide a scientific basis for optimizing early selection indices for this breed. Year of birth, type of birth, and sex were included as fixed effects, while maternal genetic effects and individual additive genetic effects were treated as random effects. A multi-trait animal model was constructed using DMU software to analyze the genetic parameters. The results showed that for growth traits at 0 months of age, heritability ranged from 0.09 to 0.64, genetic correlations from –0.03 to 0.84, and phenotypic correlations from 8.2 × 10⁻³ to 0.32. Among these, the direct heritability of body weight was 0.18, and the maternal heritability was 0.21, while cannon circumference was identified as a high-heritability trait. At 2 months of age, heritability ranged from 0.04 to 0.69, genetic correlations from −0.78 to 0.96, and phenotypic correlations from 0.036 to 0.44. Body weight, body length, and cannon circumference were high-heritability traits. At 6 months of age, heritability ranged from 0.04 to 0.71, genetic correlations from −0.32 to 0.70, and phenotypic correlations from −0.13 to 0.54. Body weight was a medium-heritability trait, while chest width and cannon circumference were high-heritability traits. At 12 months of age, heritability ranged from 0.07 to 0.48, genetic correlations from −0.04 to 0.87, and phenotypic correlations from 0.28 to 0.72. Body weight was a medium-heritability trait, whereas body height, body length, cannon circumference, and heart girth were high-heritability traits. Both body weight and cannon circumference exhibited high heritability throughout the 0–12 month period and can therefore serve as key selection indices for early breeding in this breed. The findings of this study provide essential local baseline data for the genetic improvement, breeding program design, and genetic evaluation of Pishan Red sheep.

This study focuses on the selection of hybrid combinations of Hu sheep and meat quality analysis. A comparative analysis of meat quality and volatile flavor compounds was conducted using three hybrid groups—Australian White–Hu (AH), White Suffolk–Hu (SH), and Southdown–Hu (NH)—and a pure Hu sheep group (HH) as research subjects. The results show that in terms of basic nutritional quality, the moisture content in the NH group was significantly higher than that in the HH group (p < 0.05), and the crude protein content in the NH group was significantly higher than that in the HH group (p < 0.05). Regarding physicochemical properties, the NH group had significantly higher meat color scores, L*, a*, and b* values, than the other groups (p < 0.05), along with the best tenderness and cooking yield. An analysis of amino acids, fatty acids, and volatile flavor compounds in lambs from different hybrid combinations revealed significant differences in the contents of lys, thr, asp, and his (p < 0.01). Although no significant differences were found in the fatty acid composition scores among the AH, SH, NH, and HH groups, all groups met the FAO/WHO recommended values. The NH group not only had the highest MUFA and total fatty acid content but also the highest levels of trans-petroselinic acid and trans-vaccenic acid, the two most abundant trans fatty acids. A total of 43 volatile organic compounds were detected in the four groups, among which 10 were identified as differential compounds. This study provides a scientific basis for the hybrid utilization of Hu sheep and offers technical support for the transformation and upgrading of the regional meat sheep industry.

Distinct coat morphological differences are widely observed in Inner Mongolian cashmere goats, and individuals can be classified into different hair types

Hair follicles are highly specialized mini-organs within the skin that drive the production of wool and cashmere, traits of major biological and economic importance in sheep and goats. Despite their microscopic size, hair follicles exhibit extraordinary regulatory complexity, integrating genetic programs with seasonal, endocrine, environmental, and epigenetic cues. Although transcriptional networks and signaling pathways underlying follicle morphogenesis and cycling have been extensively investigated, the post-transcriptional mechanisms that fine-tune these processes remain insufficiently understood. MicroRNAs (miRNAs) have emerged as pivotal post-transcriptional regulators that coordinate cell fate determination, lineage commitment, and tissue homeostasis. Growing evidence indicates that miRNAs play essential roles in hair follicle stem cell maintenance, proliferation, differentiation, apoptosis, and organ-level development, functioning through interconnected regulatory networks rather than isolated linear pathways. By modulating the expression of key follicle-determining genes and signaling components, miRNA-mediated regulation shapes follicle formation, cyclic regeneration, and fiber traits. In this review, we synthesize recent advances in miRNA research related to hair follicle biology, with a particular focus on wool- and cashmere-bearing mammals. We integrate findings across species to propose a systems-level framework in which miRNA networks interface with canonical signaling pathways and epigenetic mechanisms to orchestrate follicle development and regeneration. Conserved and species-specific regulatory principles are discussed to bridge fundamental follicle biology with practical applications in fiber production. Overall, this review highlights miRNAs as a critical yet previously underappreciated regulatory layer in hair follicle biology. A deeper understanding of miRNA-mediated control provides new conceptual insights into wool and cashmere development and offers a foundation for future molecular breeding and precision regulation strategies in livestock.

Temperature is the most critical factor in fish preservation. Superchilled storage represents a novel technology that effectively retards quality deterioration in aquatic products. This study investigated the flavor variation patterns and deterioration mechanisms in 16 northern pike (Esox lucius) samples during superchilled storage (−3 °C) based on analysis using gas chromatography-ion mobility spectrometry (GC-IMS) and ultra-performance liquid chromatography–quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS). The results indicate that GC-MS analysis identified 25 key volatile flavor compounds. These comprised seven ketones, thirteen alcohols, aldehydes including 2-methylbutanal, esters such as 2-heptyl acetate and methyl butyrate, as well as nitrogen-containing compounds, exemplified by pyrazines and indole. Non-targeted metabolomics further revealed four pivotal metabolic pathways, glycerophospholipid metabolism, purine metabolism, the pentose phosphate pathway, and arginine biosynthesis. These metabolic pathways were found to regulate flavor changes through modulation of lipid oxidation, nucleotide degradation, and amino acid metabolism. Notably, the arginine biosynthesis pathway exhibited significant correlations with the development of characteristic cold-storage off-flavors, mediated by glutamate accumulation and fumarate depletion. This investigation provided a theoretical foundation for optimizing preservation strategies in cold-water fish species at the molecular level.

Cashmere goats are excellent livestock breeds known for producing high-quality cashmere fibers from secondary hair follicles. In this study, we aimed to explore the key RNA molecules responsible for the differences in cashmere quality between Jiangnan cashmere goats (JNCG) and Changthangi pashmina goats (CPG). Skin transcriptomic data from the anagen, catagen, and telogen stages of hair follicle growth were retrieved from the SRA database for both JNCG and CPG. Bioinformatics analyses were conducted to identify key molecular differences underlying the variation in cashmere fiber quality. The results showed that there were 4,942 differentially expressed genes (DEGs) between JNCG and CPG through differential analysis, and the DEGs were mainly enriched in PI3K-Akt signaling pathway, Thermogenesis, ECM-receptor interaction in KEGG through functional enrichment analysis, and GO entries were mainly enriched in keratin filament, intermediate filament, keratinization. Twenty-four key candidate genes including IFG1, IGF1R, FGF5, FGF21, ND2, COX2, KRT10, KRT39, and KRT74 were further mined through pathways and entries. These genes play an important role in the development of secondary hair follicles and the formation of cashmere quality in cashmere goats, providing a theoretical basis for the genetic improvement of cashmere goats in the future.

The goat, an early domesticated ruminant, is a reliable source of cashmere, meat and milk in global agricultural production. Despite this, the genome of cashmere-rich goats has yet to be characterized. Here, we assembled the nearly complete genome of a cashmere goat from a highly economically valuable Inner Mongolian Cashmere buck, utilizing a combination of PacBio HiFi, ONT ultra-long reads, and Hi-C technologies. The size of this genome is 2.76 Gb, with a contig N50 of 95.22 Mb. All assembled sequences were anchored onto 29 autosomes and both sex chromosomes, with only two gaps present on the X chromosome. We identified 1,333.29 Mb (48.26%) of repetitive sequences and predicted 22,480 protein-coding genes. Assembly quality assessment of the genome demonstrated that our assembled cashmere goat genome surpasses the continuity, completeness, and accuracy of other published goat genomes. Taken together, we provided the first cashmere goat assembly, bridging the gap in the genome of important economic breeds of domestic goats, and providing a valuable reference resource for goat genetics and genome research.