Opportunities for detection and use of QTL influencing seasonal reproduction in sheep: a review

Notter, D. R.; Cockett, Noelle E.

doi:10.1186/1297-9686-37-s1-s39

Cited by 52 publications

(9 citation statements)

References 40 publications

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“…The data analysis additionally highlighted that the presence of at least one C allele was enough to determine a positive effect on reproductive recovery. These findings are coherent with previous research involving different breeds of sheep [ 42 , 43 ]. The haplotype analysis equally supports this finding, since H2, H3, and H4, which all exhibited the C allele at positions 20 and 21 (corresponding to SNP20-rs430181568 and SNP21-rs407388227, respectively), are associated with a shorter DTL.…”

Section: Discussionsupporting

confidence: 93%

Detection of Polymorphisms in the MTNR1A Gene and Their Association with Reproductive Performance in Awassi Ewes

Cosso

Nehme

Luridiana

et al. 2021

Animals

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The economy in Mediterranean areas is tightly linked to the evolution of the sheep-farming system; therefore, improvement in ewe’s reproductive performance is essential in the developing countries of this area. MTNR1A is the gene coding for Melatonin receptor 1 (MT1), and it is considered to be involved in the reproductive activity in sheep. The aims of this study were: (1) identifying the polymorphisms from the entire MTNR1A coding region and promoter in Lebanese Awassi sheep flocks, and (2) investigating the association between the found polymorphisms and the reproductive performance, assessed as lambing rate, litter size, and days to lambing (DTL). The study was conducted in two districts of Lebanon, where 165 lactating ewes, aged 5.2 ± 1.5 years, with body condition score (BCS) 3.3 ± 0.4, were chosen and exposed to adult and fertile rams. From 150 to 220 days after ram introduction, lambing dates and litter sizes were registered. This study provided the entire coding region of the MTNR1A receptor gene in the Awassi sheep breed. Thirty-one single nucleotide polymorphisms (SNPs) were detected, five of which were missense mutations. The H2, H3, and H4 haplotypes were associated with lower DTL (p < 0.05), as well as the SNPs rs430181568 and rs40738822721, named from now on SNP20 and SNP21, respectively. These SNPs were totally linked and can be considered as a single marker. The ewes carrying the C allele at both these polymorphic sites advanced their reproductive recovery (p < 0.05). These results are essential for improving reproductive management and obtaining advanced lambing in Awassi ewes.

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Section: Discussionsupporting

confidence: 93%

Detection of Polymorphisms in the MTNR1A Gene and Their Association with Reproductive Performance in Awassi Ewes

Cosso

Nehme

Luridiana

et al. 2021

Animals

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“…St. Croix hair lambs (n = 26) and wool lambs (n = 26) from a composite line of 50% Dorset, 25% Rambouillet and 25% Finnsheep breeding (27) were maintained at the Virginia Polytechnic Institute and State University Sheep Centre in Blacksburg, VA. The experimental design is portrayed in Figure 1; a detailed description of animal care and management is found in MacKinnon et al (28).…”

Section: Experimental Animalsmentioning

confidence: 99%

Differences in immune parameters are associated with resistance to Haemonchus contortus in Caribbean hair sheep

MacKinnon¹,

Zajac²,

Kooyman³

et al. 2010

Parasite Immunology

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Caribbean hair sheep are more resistant to gastrointestinal nematodes than conventional wool breeds, but mechanisms that confer resistance are not fully understood. This study compared immune effector cell populations and antibody concentrations in 12 hair and 12 wool lambs infected with the abomasal parasite Haemonchus contortus and sacrificed at 3 or 27 days post-infection (p.i.) and 14 uninfected animals of each breed. Faecal egg counts were over 2.5-fold higher (P = 0.12) and packed cell volumes approximately 8% lower (P < 0.10) in infected wool lambs. Abomasal lymph nodes were heavier in infected animals (P < 0.05) and infected hair sheep had larger lymph nodes than infected wool sheep (P < 0.05). Tissue eosinophil concentrations were likewise larger (P = 0.07) in hair compared with wool sheep at 3 days p.i. Circulating levels of IgE and IgA in uninfected lambs were higher in hair sheep (P < 0.05) and during infection, hair sheep had higher serum IgA than wool sheep at 3, 5, and 21 days p.i. (P < 0.05). Serum IgE in infected lambs did not differ between breeds, but concentrations of IgE in lymph nodes were higher (P < 0.01) at 27 days p.i. in infected hair sheep.

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“…An effective approach is establishing the genetic basis on non-seasonal reproduction breed for improving production in sheep. There is a variety of genes affecting non-seasonal reproduction traits in sheep have been successfully identified such as the melatonin 1A receptor (Chu et al 2003;Hernandez et al 2005;Faigl et al 2008;Mateescu et al 2009;Carcangiu et al 2011) and some clock genes that may be involved in control of seasonal breeding (Notter and Cockett, 2005). However, there were also failed to detect any association between these gene and reproductive seasonality in some ewes (Hernandez et al 2005).…”

Section: Introductionmentioning

confidence: 97%

Association between AA-NAT gene polymorphism and reproductive performance in sheep

Ding-ping¹,

Chengjiang²,

Chen³

2012

Electro Journal of Biotech

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Arylalkylamine N-acetyltransferase (AA-NAT) is critical enzyme in Melatonin (MLT) biosynthesis for MLT regulating the animal seasonal breeding. In this study, DNA sequencing methods were applied to detect the polymorphisms of the AA-NAT gene in 179 Chinese sheep belonging to two non-seasonal reproduction breeds and two seasonal reproduction breeds. One mutation at exon 3 (NM_001009461:c.486A > G) was firstly described at the sheep AA-NAT locus. Hence, we described the SmaI PCR-RFLP method for detecting EX3 486A > G mutation, frequencies of the AA-NAT-G allele varied from 0.871 to 0.908 in two non-seasonal reproduction breeds and 0.517 to 0.578 in two seasonal reproduction breeds. The associations of SmaI polymorphism with estrus traits was analyzed in non-seasonal reproduction breeds sheep and seasonal reproduction breeds sheep, the significant statistical results were found between them, the GG genotype frequencies was higher in non-seasonal reproduction breeds (p < 0.001), while, the GA genotype frequencies was higher in seasonal reproduction breeds (p < 0.05). Hence, the EX3 486A > G mutation could facilitate association analysis and serve as a genetic marker for Chinese sheep breeding and genetics.

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Opportunities for detection and use of QTL influencing seasonal reproduction in sheep: a review

Cited by 52 publications

References 40 publications

Detection of Polymorphisms in the MTNR1A Gene and Their Association with Reproductive Performance in Awassi Ewes

Detection of Polymorphisms in the MTNR1A Gene and Their Association with Reproductive Performance in Awassi Ewes

Differences in immune parameters are associated with resistance to Haemonchus contortus in Caribbean hair sheep

Association between AA-NAT gene polymorphism and reproductive performance in sheep

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