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Introduction Insulin-like growth factor 2 (IGF2) is a fetal growth and differentiation factor that plays an important role in muscle growth and in myoblast proliferation and differentiation (Giannoukakis et al. [...], Muscle growth is a complex phenomenon regulated by many factors, whereby net growth results from the combined action of synthesis and turnover. Insulin-like growth factor 2 (IGF2) is a fetal growth and differentiation factor that plays an important role in muscle growth and in myoblast proliferation and differentiation; Zinc finger, BED-type containing 6 (ZBED6)isa novel transcription factor that was identified and shown to act as a repressor of IGF2 transcription in skeletal muscle. In this study, a total of seven single nucleotide polymorphisms (SNPs) were identified, four SNPs in intron 8 of IGF2 and one promoter SNP and two missense mutations in the coding region of ZBED6, two of which were in complete linkage disequilibrium (LD) in the bovine IGF2. The 58 haplotypes were inferred in 1522 individuals representing four purebred cattle breeds from China. The seven SNPs, 79 and 66 combined diplotypes were revealed for association with body mass in Nanyang and Jiaxian cattle populations at five different ages (P < 0.05 or 0.01). The mutant-type variants and haplotype 58 (likely in LD with the beneficial quantitative trait nucleotide allele) was superior for body mass; the heterozygote diplotype of the most common haplotypes 58 was associated with higher body mass compared to either heterozygote or homozygote. The statistical analyses indicated that the mutant-type variants and haplotypes are significantly associated with body mass in study cattle populations at different ages. These data demonstrate that variants and haplotypes are associated with growth traits, and these results may provide important biological insights into the phenotypic differentiation that is associated with adaptation and specialization of cattle breeds. Key words: cattle, IGF2, ZBED6, haplotype, association analysis, growth traits. La croissance musculaire est un phenomene complexe regule par plusieurs facteurs et la croissance nette est le resultat de Taction combinee de la synthese et de la degradation. L'insulin-like growth factor 2(IGF2) est un facteur de croissance et de differenciation foetale qui joue un role important dans la croissance des muscles ainsi que dans la proliferation et la differenciation des myoblastes. Le facteur zinc finger, BED-type containing 6 (ZBED6) est un nouveau facteur de transcription qui a ete identifie et s'avere un represseur de la transcription d'IGF2 dans les muscles squelettiques. Dans ce travail, sept polymorphismes mononucleotidiques (SNP) ont ete identifies : quatre dans l'intron 8 d'IGF2, un dans le promoteur et deux mutations faux-sens dans la region codante de ZBED6, dont deux etaient en desequilibre de liaison (LD) complet au sein de l'IGF2 bovin. Au total, 58 haplotypes ont ete observes chez 1522 individus representatifs de quatre races pures de bovins de la Chine. Les sept SNP, ainsi que 79 et 66 diplotypes, respectivement, ont ete examines pour leur association avec la masse corporelle au sein des bovinsNanyang et Jiaxian a cinq ages (P < 0,05 ou 0,01). Les variants du type mutant et l'haplotype 58 (vraisemblablement en LD avec un allele QTN benefique) etaient associes a une masse corporelle accrue. Le diplotype heterozygote comprenant l'haplotype 58 etait associe a une masse corporelle accrue lorsque compare aux autres genotypes. Les analyses statistiques ont montre que les variants et haplotypes du type mutant etaient associes de maniere significative avec la masse corporelle au sein des populations etudiees a differents ages. Ces donnees demontrent que les variants et les haplotypes sont associes a la croissance et ces resultats pourraient ouvrir de nouvelles perspectives dans la comprehension de la differenciation phenotypique associee a l'adaptation et la specialisation des races bovines. [Traduit par la Redaction] Mots-cles: bovins, IGF2, ZBED6, haplotype, analyses d'association, croissance.

Introduction Sterol regulatory element-binding proteins (SREBPs) belong to the original basic helixloop- helix-leucine zipper family of transcription factors. SREBPs are transcription factors that are involved in adipogenesis, regulating the expression [...], The aim of this study was to examine the association of the SREBP-1c polymorphism with growth traits in cattle breeds. Five sequence variants (SVs) were identified within the bovine sterol regulatory element-binding protein-1c gene (SREBP-1c), using DNA sequencing, PCR, PCR-RFLP, and forced PCR-RFLP methods. These polymorphisms include three missense mutations (SV1, SV4, and SV5) in exons 7, 9, and 12, a silent mutation (SV3) in exon 9, and a large deletion (SV2) in intron 7. Overall, we report the validation of polymorphisms within the bovine SREBP-1c gene, and the haplotype variability and extent of linkage disequilibrium (LD) in 1061 individuals representing the five main cattle breeds from China. We also investigated haplotype frequencies and LD coefficients for five SVs in all study populations. LD and haplotype structure of SREBP-1c were different between breeds. The result of haplotype analysis of five SVs showed that 27 different haplotypes were identified by all breeds. Two haplotypes (Hap1 and Hap2) shared by all five populations accounted for 42.75%, 35.68%, 36.44%, 25.43%, and 96.26% of all haplotypes observed in the cattle breeds Nanyang, Qinchuan, Jiaxian, Jinnan, and Chinese Holstein, respectively. The statistical analyses indicated that one single SV and 38 combined haplotypes were significantly associated with growth traits in the Nanyang cattle population (P < 0.05 or P < 0.01). The results of this study suggest that the SREBP-lc gene possibly is a strong candidate gene that affects growth traits in the Chinese beef cattle breeding program. Key words: cattle, haplotype combination, SREBP-lc gene, sequence variants, growth traits. Le but de ce travail etait d&apos;examiner l&apos;association entre le polymorphisme au sein du gene SREBP-1c et la croissance chez les bovins de boucherie. Cinq variants de sequence (SV) ont ete identifies au sein du gene bovin codant pour la proteine 1c de liaison a l&apos;element de regulation des sterols (SREBP-1c) au moyen du sequencage, de la PCR, de la PCRRFLP et de la PCR-RFLP forcee. Ces polymorphismes incluent trois mutations faux-sens (SV1, SV4 et SV5) dans les exons 7, 9 et 12, une mutation silencieuse (SV3) dans l&apos;exon 9 et une grande deletion (SV2) dans l&apos;intron 7. Globalement, les auteurs rapportent la validation des polymorphismes au sein du gene SREBP-1c bovin, ainsi que l&apos;analyse de la variabilite des haplotypes et le desequilibre de liaison (LD) chez 1061 individus representatifs des cinq principales races de bovins en Chine. Les auteurs ont egalement determine la frequence des haplotypes et les coefficients LD pour les cinq variants chez toutes les populations etudiees. Le LD et la structure des haplotypes pour SREBP-1c etaient differents au sein des diverses races. L&apos;analyse des haplotypes pour les cinq variants a permis d&apos;identifier 27 haplotypes differents chez ces populations. Les deux haplotypes presents chez toutes les populations (Hap1 et Hap2) representaient respectivement 42,75, 35,68, 36,44, 25,43 et 96,26 % des tous les haplotypes observes chez les races Nanyang, Qinchuan, Jiaxian, Jinnan et Chinese Holstein. Les analyses statistiques ont indique qu&apos;un seul variant et 38 haplotypes combines etaient significativement associes a la croissance chez les bovins de la population Nanyang (P < 0,05 ou P < 0,01). Les resultats de cette etude suggerent que le gene SREBP-1c serait possiblement un gene candidat affectant la croissance au sein du programme chinois d&apos;amelioration genetique du bovin de boucherie. Mots-cles : bovin, combinaison d&apos;haplotypes, gene SREBP-1c, variants de sequence, caracteres de croissance. [Traduit par la Redaction]

Copy number variation (CNV) is a form of genetic variation caused by genome rearrangement, with abnormal fragments ranging from 50 bp to Mb. And, CNV is closely related to disease, growth and reproductive shape of livestock. As a member of myosin light chain kinase (MYLK) family with serine/threonine specificity, MYLK4 belongs to an enzyme encoded by MYLK4 gene. Although MYLK4 is a recognized kinase, its function has yet to be revealed in subsequent studies. This study aims to analyze CNV and genetic effects of MYLK4 gene in goats. We used qPCR to detect CNV of MYLK4 gene in African Nubian goat (n = 32), Guizhou black goat (n = 196) and Guizhou white goat (n = 95), respectively, and correlated CNV data of MYLK4 gene with goat growth traits in Chinese goats. The results showed that the effect of MYLK4 gene CNV on body weight, body length and body height of goats had significantly different (p < 0.05, Q < 0.05), in which CNV showed better growth traits in type of deletion. Therefore, CNV of MYLK4 gene can be used as a molecular marker for assisted selection of goat growth traits, which provides a theoretical basis for the genetic improvement of goat breeds in China. [ABSTRACT FROM AUTHOR]

The Xinjiang brown cattle, Red steppe cattle, and Yunling cattle are indigenous cultivated cattle breeds in Chinese frontier provinces, and they produce high-grade beef and milk products, however, their genetic diversity in many important genes related to excellent meat and milk production is still unknown. Our previous studies have found that several candidate genes (e.g., SREBP1c and PAX7) were associated with bovine economically important phenotypic traits, but none has been reported in the above-mentioned three cattle breeds. Since the InDel (insertion/deletion) marker becomes a useful tool applied in the animal molecular breeding, herein, we firstly found that the InDel variations of seven candidate genes in these cattle. Results showed that the genotypic and allelic distributions of these seven genes were remarkably different among these three cattle (p < 0.05 or p < 0.01). Furthermore, the InDel variations of SREBP1c and PAX7 genes were significantly associated with eight phenotypic traits in Xinjiang brown cattle (p < 0.05 or p < 0.01), respectively, suggesting that they can become the useful DNA markers. [ABSTRACT FROM AUTHOR]

Copy number variations (CNVs) have been identified as another important structural variation of genome. In recent years, a large amount of CNVRs have been identified in humans and animals. However, association and dosage effects studies of CNVs are very limited. Apolipoprotein L3 (APOL3) gene plays a central role in modulating gene transcription and is located within a CNVR that encompasses quantitative trait locis (QTLs) for economic traits like meat quality. Herein, we analyzed the CNV polymorphism of APOL3 in 421 individuals from five distinct cattle breeds, and then correlated their genotypes with growth traits. Association analysis revealed that the APOL3 CNV was significantly associated with hip height and cannon circumference of Xianan (XN) cattle (P <.01), and visibly associated with body slanting length and hucklebone width of Pinan (PN) cattle (P <.05). Overall, the data provide evidence for the functional role of APOL3 CNV and a basis for future applications in cattle breeding. [ABSTRACT FROM AUTHOR]

Serine protease inhibitor protein 3 (serpin peptidase inhibitor, clade A, member 3, SERPINA3) is a member of the serpin superfamily, probably related to the yield and quality of muscle. This study focuses on the relationship between SERPINA3 gene polymorphism and growth traits in beef cattle. The study first uses sequencing pooled DNA samples (Pool-Seq), PCR-RFLP and Tetra-primer ARMS-PCR techniques to determine the genetic polymorphisms of SERPINA3 in 765 beef cattle. Then, the polymorphic loci were correlated with the growth characters of cattle. Five SNPs (SNP1:A-648G, SNP2:T6496A, SNP3:G2495A, SNP4:T2595A, SNP5:A2615G) were found, located in the promoter, introns 5 and SNP 3, 4, 5 were in exons 2, respectively. The observed He was from 0.44 to 0.5, Ne were approaching 2 (1.78 to 2.00). The maximum and minimum PIC (polymorphism information content) values were 0.37 and 0.34, respectively. The association analysis results showed that the SNPs had a significant height in the chest girth and body length. (p < 0.05 or p < 0.01). This will provide important information for the rapid breeding of Chinese yellow cattle and the establishment of a molecular genetic marker database. [ABSTRACT FROM AUTHOR]