SNPs at exonic region of aquaporin-7 (AQP7) gene may affect semen quality parameters among crossbred bulls

Gene expression analysis of Aquaporin genes in ruminants during growth phase in response to heat stress

Aquaporins (AQPs) are trans-membrane protein involved in water transport and different cellular functions such as cell adhesion, signalling and proliferation. These membrane proteins are essential for key physiological functions such as organ development, osmoregulation, tissue regeneration and metabolism. The regulation of AQP5 gene expression in ruminants during growth phase has not been analysed in-vivo. Therefore, the gene expression pattern was analysed in Jamunapari goats during 3 months to 12 month of age and adult age group in response to heat stress. The genotyping of the AQP5 gene was carried out by High-Resolution Melting (HRM) in four different goat breeds, which indicated four distinct genotypes in the population. The nucleotide diversity for the AQP5 gene ranged from 0.315 and 0.524 across the breeds. Additionally, a close evolutionary relationship between AQP5 and the HSP70 gene was observed, indicating a shared pathway for heat stress regulation. The m-RNA expression level of AQP5 at 3, 9, 12 month and adult age group exhibited 47.24, 1140, 43.17 and 12.55-fold higher expression than control. The m-RNA expression level of the AQP5 gene was up-regulated and significantly higher (P < 0.05) at 9-month age as compared to the other age groups. Heat stress phenotypes were classified based on respiration rate and heart rate, and the m-RNA expression of AQP5 was higher in heat stress-susceptible (HSS) individuals than heat stress-tolerant (HST) individuals at 3, 9, and 12 months of age. The AQP5 plays a significant role in thermoregulation during growth phases in response to heat stress in goats, however, it is required to understand the role of aquaporins at cellular level as well as to establish the association with production performance in ruminant system in-vivo.

Polymorphisms of aquaporin 7 (AQP7) gene in Madura bulls (Bos indicus)

In this study, a PCR-RFLP method was employed to investigate the evidence of two mutation sites in exon 2 (c.N8S) and exon 3 (c.E36Q) regions of AQP7/TaaI gene in Madura bulls. Both mutation sites were polymorphic with presence of three genotypes. However, a mutation of c.N8S had the moderate PIC value (>0.30). Hence, it can be suggested that the mutation of c.N8S can be used for the genetic marker of sperm quality traits in Madura bulls. However, the association study with 15 selected Madura bulls revealed that there are no significant association between c.N8S and sperm quality traits. However, the mutation of c.N8S in animal studies was not associated with sperm quality traits of sperm volume, progressive motility sperm concentration and daily sperm viability. In future, a further research with large number of animal samples and records data are important to obtain the genetic markers for productivity traits accurately.

Development of a RAPD marker-based classification criterion for quality semen production in Holstein crossbred bulls

In cattle production systems, an intense selection pressure for production traits has resulted in the decline of fertility traits. To optimize an efficient reproduction system, the inclusion of both male and female fertility traits in the selection process is very much essential. RAPD (Random Amplified Polymorphic DNA) was developed as a molecular biology tool and has been extensively used, to study intra- and interspecific genetic diversity. The present study was undertaken to utilize RAPD primers to investigate the association between DNA markers and semen quality traits viz. Sperm concentration, total sperm count ejaculate and initial sperm motility and thereby to identify good/poor semen producers. DNA isolated from the blood samples of healthy bulls was subjected to RAPD-PCR. The multiple regression analysis followed by independent t test was carried out to identify suitable markers. Based on the results, only 12 bands were identified as marker suitable for any of the quality trait. This includes, OPA2 ~ 760, OPA2 ~ 700, OPA6 ~ 1,200, OPA9 ~ 400, OPA9 ~ 380, OPA12 ~ 970, OPA14 ~ 715, OPA14 ~ 605, OPA16 ~ 485, OPA17 ~ 860 and OPA18 ~ 480. Multiple regression analysis selected, OPA2 ~ 760 and OPA2 ~ 1,750 for sperm concentration and OPA2 ~ 760, OPA2 ~ 700, OPA9 ~ 620, OPA4 ~ 670 and OPA18 ~ 1,015 for total sperm count/ejaculate. But the t test revealed a significant association between OPA2 ~ 760 and total sperm count. Further, discriminant function analysis also identified this marker in the first step itself. The results of the present study can be exploited as a low-cost alternative strategy for identification of good /poor semen producers in crossbred bulls at an early age.

The Study of the Response of Fat Metabolism to Long-Term Energy Stress Based on Serum, Fatty Acid and Transcriptome Profiles in Yaks

Simple Summary

The serum, fatty acid and transcriptome profiles in the subcutaneous fat of yaks were measured to explore the effect of long-term energy stress (ES) on fat metabolism during the cold season. The study indicated that under long-term ES during the cold season, the amount of fat in yaks was less, and fat mobilization was one of the main ways by which energy was obtained in yaks. Yaks regulated fat metabolism in subcutaneous fat primarily through adenosine 5′-monophosphate-activated protein kinase (AMPK) signaling. Glucose (GLU) intake, fat catabolism, fatty acid synthesis and fatty acid oxidation in the subcutaneous fat of yaks were all inhibited, which resulted in the fat mobilization of yaks slowing as much as possible under long-term ES. In addition, the energy expenditures in fat cells were inhibited by regulating phosphatidylinositol 3’ -kinase (PI3K)-serine/threonine-protein kinase (Akt) andmammalian target of rapamycin (mTOR) signaling, and the limited energy obtained from GLU and fat was consumed by muscle and organs as much as possible. These factors led to an energy balance in yaks under long-term ES. The fat stored in yaks can be expended for as long as possible, and yaks can survive for as long as necessary under long-term ES.

Abstract

Long-term energy stress (ES) during the cold season is a serious problem for the breeding of yaks. In this paper, the response of fat metabolism in yaks to long-term ES during the cold season was studied. Gas chromatography (GC) analysis showed that the percentage of saturated fatty acids (SFAs) in the subcutaneous fat of the yaks in the ES group was 42.7%, which was less than the 56.6% in the CO group (p < 0.01) and the percentage of polyunsaturated unsaturated fatty acids (PUFAs) in the subcutaneous fat of the yaks in the ES group was 38.3%, which was more than the 26.0% in the CO group (p < 0.01). The serum analysis showed that fatty acid oxidation in yaks was increased under long-term ES. In the subcutaneous fat of yaks under long-term ES, the gene expression levels of glycerol-3-phosphate acyltransferase 4 (GPAT4), hormone-sensitive lipase (HSL), patatin-like phospholipase domain-containing protein 2 (PNPLA2), acyl-CoA dehydrogenase (ACAD), acyl-coenzyme A thioesterase 8 (ACOT8), facilitated glucose transporter (GLUT4), 3-oxoacyl-[acyl-carrier-protein] synthase (OXSM), oestradiol 17-beta-dehydrogenase 8 (HSD17B8) and malonate-Co-A ligase ACSF3 (ACSF3) were downregulated (q < 0.05), whereas the gene expression levels of aquaporin-7 (AQP7), long-chain-fatty-acid-CoA ligase (ACSL), elongation of very long chain fatty acids protein (ELOVL) and fatty acid desaturase 1 (FADS1) were upregulated (q < 0.05), indicating the inhibition of fat catabolism, fat anabolism, fatty acid oxidation, glucose (GLU) intake and SFA synthesis and the promotion of glycerinum (GLY) transportation and PUFA synthesis. Additional findings showed that the gene expression levels of leptin (LEP), adenosine 5′-monophosphate-activated protein kinase (AMPK) and phosphatidylinositol 3-kinase (PI3K) were upregulated (q < 0.05), whereas the gene expression levels of malonyl-CoA decarboxylase (MCD), sterol regulatory element-binding protein 1 (SREBF1), mammalian target of rapamycin (mTOR) and serine/threonine-protein kinase (AKT) were downregulated (q < 0.05), indicating that fat metabolism in the subcutaneous fat of yaks under ES was mainly regulated by AMPK signaling and mTOR and PI3K-AKT signaling were also involved. Energy consumption was inhibited in the subcutaneous fat itself. This study can provide a theoretical basis for the healthy breeding and genetic breeding of yaks.

Evolution of Frieswal cattle: A crossbred dairy animal of India

Frieswal cattle is one of the crossbred strains having 5/8 Holstein Friesian and 3/8 Sahiwal inheritance, develo pedby ICAR-Central Institute for Research on Cattle, Meerut, in collaboration with Ministry of Defence. The projectwas started in 1987 for the evolution of a new crossbred national milch breed: Frieswal – (Holstein×Sahiwal), yielding 4,000 kg of milk with 4% butter fat in a mature lactation of 300 days. It is the only project in the country where such a huge population of animals (more than 20,000) is available with accurate production and pedigree records of each and every animal over generations, with well-established progeny testing network in 37 military farms to cover all the agro-climatic zones of the country. In this review, an attempt has been made to analyze the genesis, present status and future prospects of Frieswal cattle in India.