Single nucleotide polymorphisms at heat shock protein 90 gene and their association with thermo-tolerance potential in selected indigenous Nigerian cattle

Effect of access to natural shade on scrotal thermoregulatory capacity, integrity of the testicular parenchyma and sperm morphology of Nelore (Bos indicus) and Canchim (Bos taurus x Bos indicus) bulls

The objective of this work was to evaluate the effect of using naturally shaded pastures on scrotal thermoregulatory capacity, testicular echotexture, and sperm morphology of Nelore (Bos indicus) and Canchim (5/8 Bos taurus x 3/8 Bos indicus) bulls in a tropical climate region. Sixty-four adult Nelore and Canchim bulls were used, equally allocated in Full Sun (FS, n = 32) or Crop-Livestock-Forestry (CLF, n = 32) pasture systems. During five consecutive climate seasons, the bulls underwent monthly breeding soundness evaluations and the biometeorological variables in the systems were continuously monitored. Microclimate was significantly different between systems. CLF system had lower BGHI than FS throughout the experimental period. No triple interaction (Season x Breed x Treatment, P > 0.05) was observed for any of the variables. Animals in CLF showed lower body temperature in Summer (FS:39.41 ± 0.05 vs. CLF:39.30 ± 0.05 °C; P = 0.005) and in Autumn (FS:39.54 ± 0.05 vs. CLF:39.35 ± 0.05 °C; P = 0.005). Access to shading did not determine differences in the evolution of scrotal biometry, temperatures, and scrotal thermal gradients (P > 0.05). Regardless of breed, animals in CLF showed greater right testicular volume (FS:247.5 ± 5.7 vs. CLF:259.0 ± 5.7 cm³; P < 0.05), more suitable parenchyma echotexture, and fewer microlithiasis spots in the Spring and Summer. Testosterone concentration was higher in FS (FS:2.6 ± 0.2 vs. CLF:2.1 ± 0.2 ng/mL; P = 0.035). Canchim bulls presented higher total sperm defects during the Autumn and Winter (P = 0.010), but the total defects levels for Canchim and Nelore bulls were in normal range for adult bulls. Thus, the natural shade in CLF system was effective in improving the microclimate of pastures and minimizing adverse environmental effects on some reproductive features of interest in beef cattle.

Association analysis of HSP90AA1 polymorphism with thermotolerance in tropically adapted Indian crossbred cattle

Raising cattle is a lucrative business that operates globally but is confronted by many obstacles, such as thermal stress, which results in substantial monetary losses. A vital role of heat shock proteins (HSPs) is to protect cells from cellular damage. HSP90 is a highly prevalent, extremely adaptable gene linked to physiological resilience in thermal stress. This study aimed to find genetic polymorphisms of the HSP90AA1 gene in Karan Fries cattle and explore their relationship to thermal tolerance and production traits. One SNP (g.3292 A > C) was found in the Intron 8 and three SNPs loci (g.4776 A > G, g.5218T > C and g.5224 A > C) were found in the exon 11 of 100 multiparous Karan Fries cattle. The association study demonstrated that the SNP1-g.3292 A > C was significantly (P < 0.01) linked to the variables respiratory rate (RR), heat tolerance coefficient (HTC) and total milk yield (TMY (kg)) attributes. There was no significant correlation identified between any of the other SNP sites (SNP2-g.4776 A > G; SNP3-g.5218T > C; SNP4-g.5224 A > C) with the heat tolerance and production attributes in Karan Fries cattle. Haploview 4.2 and SHEsis software programs were used to analyse pair linkage disequilibrium and construct haplotypes for HSP90AA1. Association studies indicated that the Hap3 (CATA) was beneficial for heat tolerance breeding in Karan Fries cattle. In conclusion, genetic polymorphisms and haplotypes in the HSP90AA1 were associated with thermal endurance attributes. This relationship can be utilized as a beneficial SNP or Hap marker for genetic heat resistance selection in cow breeding platforms.

Potentials of single nucleotide polymorphisms and genetic diversity studies at HSP90AB1 gene in Nigerian White Fulani, Muturu, and N'Dama cattle breeds

The study was aimed at genetic characterization of Nigerian breeds of Muturu, N'Dama, and White Fulani cattle breeds at heat shock protein 90AB1 locus. Also, the goal of the study was to detect the presence of single nucleotide polymorphisms (SNPs) at HSP90AB1 locus and consequently recommend them as bio-markers for thermo-tolerance potentials in Nigerian cattle breeds when exposed to assaults of thermal conditions/heat shock of tropical environment. Based on the previously published potentials of this candidate gene to lower assaults of thermal conditions/heat shock such as heat stress, the detected SNPs of HSP90AB1 within the population of the Nigerian cattle in this study will be recommended for population-based screening with a view to genetically improving those zebu cattle breeds that are more vulnerable to heat shock and assaults of thermal conditions. Total number of 200 blood samples were randomly collected from White Fulani (84 samples), Muturu (73 samples), and N'Dama (43 samples) breeds of cattle. Out of these, 20 DNA samples were randomly selected from each of the three cattle breeds and were used for DNA extraction and downstream analyses to further confirm findings of previous study, hence the goal of our study. DNA was extracted from the blood samples using the Zymo-bead DNA extraction kit and DNA sequencing of our samples was performed. A total number of 9 SNPs (within exons 5-6 coding regions) and 11 SNPs (within exons 12-13 coding regions) were detected at HSP90AB1 locus using the codon code aligner software. ARLEQUIN 2.0001 software was used to estimate the basic population genetic statistics while the DnaSP version 5.10.01 was used to estimate the genetic diversity indices. This study detected new SNPs (polymorphic sites) at HSP90AB1 locus within the DNAs of Nigerian White Fulani (WF), Muturu (MU), and N'Dama (ND) breeds of cattle. Within exons 5-6 coding regions, the N'Dama (ND) cattle breed had the highest for number of SNPs (5) and genetic diversity indices while White Fulani (WF) and Muturu (MU) had the least (2) number of SNPs each. Within exons 12-13 coding regions, WF had the highest numbers of SNPs (7) and genetic diversity indices while MU had the least number of SNPs (1) and genetic diversity indices. Some of the detected SNPs at HSP90AB1 locus were shared among the three breeds, suggesting that these three Nigerian cattle breeds showed shared ancestral alleles and lineage. Our study further revealed that HSP90AB1 is highly polymorphic/variable and diverse among the three Nigerian cattle breeds examined. Based on the previously documented thermo-tolerance potentials of members of HSP90 sub-family including the findings of our study, we hypothesize therefore that the presence of SNPs of HSP90AB1 within the DNAs of these three breeds of Nigerian cattle (WF, ND, and MU) may confer them thermo-tolerance potentials for thermal assault conditions and heat shock of the tropics at HSP90AB1 locus. Therefore, the detected SNPs can be recommended as bio-markers to improve the thermo-tolerance potentials of Nigerian breeds of zebu cattle raised under the challenges of heat shock for better adaptation and survival.

Techniques of Using Peripheral Blood Mononuclear Cells as the Cellular System to Investigate How of the Bovine Species (Indian Zebu-Jersey Crossbreds) Responds to in vitro Thermal Stress Stimulation (Thermal Assault/Heat Shock)

Animal production is negatively impacted by global warming and is subject to serious consequences for livestock production systems. In order to understand how PBMCs of Indian Zebu-Jersey crossbreds respond to various levels and durations of thermal assault and heat shock, in this chapter we will discuss techniques involving in vitro thermal stress stimulation (TSS) to stimulate bovine peripheral blood mononuclear cells (PBMCs) under various thermal assault conditions (TACs), including normal to extreme temperatures and varying durations of thermal exposure (DTEs). The consequences of thermal stress on bovine species can be lessened and managed with an understanding of how PBMCs as a cellular system respond to in vitro heat shock and thermal assault. To learn more about how Indian Zebu-Jersey crossbreds respond to in vitro thermal conditions, it may also be possible to explore the relationship between the decrease in PBMCs count during in vitro TSS and the expression of the heat shock protein genes (HSPs) such as HSPs 70 and 90 genes. This will be exploited to discover how Indian Zebu-Jersey crossbreds respond in vivo to diverse environmental thermal conditions and will further enable in vivo understanding of the potential for thermotolerance in bovine species for better adaptability, survival, and production performance.

Genome centric engineering using ZFNs, TALENs and CRISPR-Cas9 systems for trait improvement and disease control in Animals

Livestock is an essential life commodity in modern agriculture involving breeding and maintenance. The farming practices have evolved mainly over the last century for commercial outputs, animal welfare, environment friendliness, and public health. Modifying genetic makeup of livestock has been proposed as an effective tool to create farmed animals with characteristics meeting modern farming system goals. The first technique used to produce transgenic farmed animals resulted in random transgene insertion and a low gene transfection rate. Therefore, genome manipulation technologies have been developed to enable efficient gene targeting with a higher accuracy and gene stability. Genome editing (GE) with engineered nucleases-Zinc finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs) regulates the targeted genetic alterations to facilitate multiple genomic modifications through protein-DNA binding. The application of genome editors indicates usefulness in reproduction, animal models, transgenic animals, and cell lines. Recently, CRISPR/Cas system, an RNA-dependent genome editing tool (GET), is considered one of the most advanced and precise GE techniques for on-target modifications in the mammalian genome by mediating knock-in (KI) and knock-out (KO) of several genes. Lately, CRISPR/Cas9 tool has become the method of choice for genome alterations in livestock species due to its efficiency and specificity. The aim of this review is to discuss the evolution of engineered nucleases and GETs as a powerful tool for genome manipulation with special emphasis on its applications in improving economic traits and conferring resistance to infectious diseases of animals used for food production, by highlighting the recent trends for maintaining sustainable livestock production.

Exploiting morphobiometric and genomic variability of African indigenous camel populations-A review

Camels (Camelus dromedarius) in Africa are adapted to arid and the semi-arid environmental conditions, and are valuable for meat, milk and fiber production. On account of the growing demand for camels in this continent, there is a need for knowledge on their phenotypic and genetic diversity. This is fundamental to sustainable herd management and utilization including the design of appropriate breeding and conservation strategies. We reviewed studies on the phenotypic and genetic characterization, breeding objectives, systems of production, productive and reproductive performances, and pathways for the sustainable rearing and use of camels in Africa. The morphological and genetic diversity, productive and reproductive abilities of African camels suggest the existence of genetic variations that can be utilized for breeds/ecotypes' genetic improvement and conservation. Possible areas of intervention include the establishment of open nucleus and community-based breeding schemes and utilization of modern reproductive technologies for the genetic improvement of milk and meat yields, sustainable management of rangelands, capacity building of the pastoralists and agro-pastoralists, institutional supports, formation of centralized conservation centres and efficient and effective marketing systems.

Genetic polymorphism in HSPB6 gene and their association with heat tolerance traits in Indian Karan Fries (Bos taurus x Bos indicus) cattle

Heat shock proteins (HSPs) act as a chaperone activity ensuring the folding, unfolding, and refolding of denatured proteins, which help in a protective role during thermal stress in dairy cattle. This study aimed to detect genetic variations of the HSPB6 gene and to determine their association with heat tolerance traits in Karan Fries cattle. Five single nucleotide polymorphisms (SNPs) (SNP 1-5) were reported in the Karan Fries cattle, which included three transitions viz. SNP1-g.161G > A, SNP2-g.436G > A, and SNP4-g.2152A > G and two transversions viz. SNP3-g.1743C > G, SNP5-g.2417A > T. The association analysis revealed that the three SNPs loci i.e., SNP1-g.161G > A, SNP2-g.436G > A, and SNP3-g.1743C > G were significantly (p < 0.01) associated with the respiration rate (RR) and rectal temperature (RT) (°C) traits. Furthermore, in the case of heat tolerance coefficient (HTC) trait was found significantly associated (p < 0.01) with SNPs loci i.e., SNP1-g.161G > A, SNP2-g.436G > A, and SNP3-g.1743C > G. The Hap 4 (GACAT) was found to more adaptable than cattle of other haplotypes as reflected by lower values of RR, RT and HTC. This study provides the first association analyses between the SNPs and haplotypes of HSPB6 gene and heat tolerance traits in Karan Fries cattle, which could be used as effective SNP markers in genetic selection for heat tolerance in cattle breeding program.

Exposure to high thermal conditions for a long time induces apoptosis and decreases total RNA concentration in peripheral blood mononuclear cells among Indian Zebu–Jersey crossbreds

Background and Aim:

Global warming has grave consequences on livestock production systems and profound negative effects on animal production. This study aimed to carry out an in vitro thermal stress stimulation (TSS) of bovine peripheral blood mononuclear cells (PBMCs) using different thermal assault conditions (TACs), including normal to extreme temperatures and varying durations of thermal exposure (DTE) to understand how PBMCs of Indian Zebu–Jersey crossbreds respond to various levels and durations of heat shock.

Materials and Methods:

Ten milliliters of blood were collected from 70 Indian Zebu–Jersey crossbreds under aseptic conditions and were sampled for isolating PBMCs. Peripheral blood mononuclear cells were divided into seven groups, each comprising 10 PBMC samples isolated from 10 different animals. Aliquots of 500 μL of PBMCs were stressed by exposure to different TACs (37, 40, and 45°C) for DTEs of 3 or 6 h. Subsequently, the cells were harvested. The control unstressed samples (500 μL aliquots of PBMCs) were exposed to no TAC (0°C) and zero DTE (0 h). Total RNA from all the treatment groups of PBMCs were isolated and quantitated.

Results:

We found a very strong association between TACs and RNA levels. In addition, PBMCs viability was negatively affected by heat shock. This led to an exponential reduction in PBMC count as TACs toughened. Only 3.59 × 10⁵ ± 0.34 cells/mL were viable after exposure to 45°C for a 6 h DTE. This cell viability was lower than that measured in controls subjected to no stress and zero time DTE (2.56 × 10⁷ ± 0.22 cells/mL). We also observed a reduction in the concentration of RNA isolated from thermally stressed PBMCs.

Conclusion:

In vitro TSS of PBMCs provided biological information on the response of cellular systems to heat shock after exposure to TACs. This will help to mitigate and manage the effects of thermal stress in bovine species. The association between the reduction in PBMC count after in vitro TSS and the expression of heat shock protein 70 gene will be investigated in the future to further understand how Indian Zebu–Jersey crossbreds respond to in vitro thermal conditions. This will be used to determine the in vivo response of Indian Jersey crossbreds to different environmental thermal conditions and will further enable the in vivo understanding of thermotolerance potentials of bovine species for better adaptation, survival, and production performance.

Heterozygous Single-Nucleotide Polymorphism Genotypes at Heat Shock Protein 70 Gene Potentially Influence Thermo-Tolerance Among Four Zebu Breeds of Nigeria

Genetic variants at heat shock protein 70 gene and their influence on heat stress (HS) tolerance were studied among selected Nigeria zebu, namely, 25 White Fulani (WF), 21 Sokoto Gudali (SG), 21 Red Bororo (RB), and 23 Ambala (AM). Detection of single nucleotide polymorphism (SNP) followed by determination of genotype and genotypic frequency was made among the selected breeds. The heat tolerance coefficient (HTC) was determined from thermo-related parameters including body temperature, rectal temperature, and respiratory rate. Thermo-Tolerance was evaluated through the SNP-thermo-parameter relationship. Statistical analyses were done using the GLM procedure in SAS. A quantitative real-time/high-resolution melting-based assay detected twelve genetic variants. Five of these were common and shared across all breeds of cattle. Of the remaining seven variants, three were specifically identified in AM, two in SG, and two in RB. Also, SNPs were evaluated and four unique SNPs (C151T, C146T, G90A, and C219A) were identified. Heterozygous animals had lower HTC suggesting their potential to withstand HS than homozygous counterparts. The WF and RB animals had significantly lower values for all parameters (BT, RT, RR, and HTC) compared to AM and SG breeds. Thermo-related parameters were significantly different (P < 0.001), and it is recommended that screening of SNPs in zebu is needed to enable selection for improved thermo-tolerance.