Organisms have the capacity to detect day-night fluctuations through oscillators regulated by circadian clock genes, which are crucial for regulating various biological processes. Numerous studies have demonstrated a marked association between these genes and various growth traits of sheep. This study identified polymorphisms at 23 potential loci within five clock genes in four Chinese sheep breeds. Only two polymorphic insertion/deletions (InDels) were detected in CLOCK and PER3 genes, respectively. The distribution of these two loci in four Chinese sheep breeds and their association with growth traits were further explored. A 12 bp deletion was found in the intron of the CLOCK gene (rs604230640), which was significantly associated with body height (p < 0.05), body oblique length (p < 0.05) and cannon girth (p < 0.05) in Hu sheep (HS). A 22 bp insertion in the intron of the PER3 gene (rs600537720) with a dominant genotype of insertion/insertion (II) was found to have a significant association with chest depth (p < 0.05) in Small-Tail Han sheep (STHS), tail width (p < 0.05) in Tong Sheep (TS), and in Lanzhou fat-tailed sheep (LFTS). In conclusion, this study has elucidated the polymorphisms of CLOCK and PER3 genes and has examined the influence of these two genes on the growth traits of sheep. Concurrently, the two molecular markers identified in CLOCK and PER3 could potentially serve in the marker-assisted selection of growing-related traits in local Chinese sheep breeds.

为探究獭兔和伊高乐肉兔杂交后代生长发育的规律,并为其杂种后代的选种选配和饲养管理提供科学依据,实验选用獭兔和伊高乐肉兔作为亲本,测定正反交F1 代的体重和体尺,并利用Logistic、Gompertz和Von Bertallanffy模型拟合正反交后代 0～17 周龄的生长曲线.结果表明:獭肉杂交(TR组)在 75 日龄、90 日龄及 120 日龄的体重均高于肉獭杂交(RT组)(P<0.05),在 11 周龄后 2 组体重增长趋势开始发生变化,TR组生长速度相比RT组更快;Logistic、Gompertz和Von Bertallanffy模型对正反交F1 代体重均具有较高的拟合度(R2>0.993),其中Logistic模型对正反交后代的拟合效果最佳;在 120 日龄时,TR组与RT组的胸围差异显著,2 组体尺的生长模型拟合度均在 0.978 以上.研究结果可为獭兔和肉兔的杂交利用提供理论依据.

Objective: The Janus kinase/signal transducer and transporter activator (JAK/STAT) signaling pathway plays crucial roles in lipid metabolism, glucose metabolism and cell senescence, suggesting that they are potential candidate genes affecting growth traits in animals. The present study aimed to evaluate the association between InDels in the JAK/STAT pathway and growth traits of four Chinese sheep breeds, including Tong sheep, Hu sheep, Small-tailed Han sheep and Lanzhou fat-tailed sheep.Results: Seventy-six indel loci of 11 genes in JAK/STAT were detected, and three genotypes were selected at four loci by PCR amplification, electrophoresis and sequencing, including one locus in STAT3, one locus in STAT5A, and two loci in JAK1. The Correlation analysis indicated that there was no significant correlation between STAT3 and growth traits in four sheep breeds (P > 0.05); STAT5A was significantly associated with body height, rump width and tube circumference in Hu sheep and body length in Tong sheep (P < 0.05); JAK1 was significantly correlated with body height, body oblique length, cross height and tube circumference in Hu sheep (P < 0.05) and body oblique length, cross height and tube circumference in small-tailed Han sheep (P < 0.05).Conclusion: Overall, our results indicated a potential association between the growth traits of sheep and the InDels of JAK1 and STAT5A.

甜菜碱广泛存在于动植物体内,是甘氨酸的三甲基衍生物,常作为一种多功能性添加剂添加于畜禽饲料中.甜菜碱可通过影响猪的采食量、肠道发育、糖脂代谢及血清生长激素水平等促进仔猪、保育猪及育肥猪的生长发育.在畜禽生产上,使用甜菜碱部分替代胆碱及蛋氨酸还可以降低饲料成本,提高养殖效益.对此,该文根据近年来甜菜碱对不同生长发育阶段猪的饲喂效果及其调控机制进行分析,以期为其在猪生产中的高效应用提供参考依据.

蜱虫病是被蜱虫叮咬而感染,造成牛充血、水肿和继发性病症;锥虫病是感染锥虫后引起牛贫血、黄疸、高热、体表浮肿等.由于牛的品种不同以及生活环境的差异,导致牛对蜱虫病和锥虫病的抗性不同,加大了防治和研究的难度.寄生虫寄生于畜体中,就会和宿主产生一定的互作关系,引起机体代谢、信号转导、基因表达等发生变化.因此,从分子机制入手可以更深入了解致病原因和抗病机理.该文主要从牛蜱虫病与锥虫病概况、牛对蜱虫病与锥虫病的抗虫性能、牛抗蜱虫病与抗锥虫病的分子机制3个方面进行综述,以期为牛寄生虫病防治和培育优良牛品种提供理论基础.