RESUMO
The polypeptide N-acetylgalactosaminyltransferase-like protein 5 (GALNTL5) is a newly identified protein that is specifically expressed in testis tissue and participates in spermatogenesis. In this study, we characterized a novel bovine GALNTL5 splice variant, designated as GALNTL5-AS, by using real-time polymerase chain reaction (RT-PCR) and clone sequencing methods. The novel GALNTL5 isoform was derived from the complete transcript, GALNTL5-complete, via alternative splicing (AS). The pattern of the splice variant was exon skipping. Bovine GALNTL5 transcripts were expressed in the testis, as demonstrated by RT-PCR. The expression levels of both transcripts were higher in adult testes than in calf testes (P < 0.05). In addition, prediction analysis showed that the GALNTL5-AS transcript only encoded 122 amino acids and lost its glycosyltransferase 1 and Gal/GalNAc-T motifs, which may result in a dysfunctional protein compared with the predominant transcript GALNTL5-complete. This study improves our understanding of the bovine GALNTL5 gene function during bull sperm formation.
Assuntos
Processamento Alternativo , N-Acetilgalactosaminiltransferases/genética , Testículo/metabolismo , Motivos de Aminoácidos , Animais , Bovinos , Éxons , Isoenzimas/química , Isoenzimas/genética , Isoenzimas/metabolismo , Masculino , N-Acetilgalactosaminiltransferases/química , N-Acetilgalactosaminiltransferases/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismoRESUMO
Polymorphonuclear neutrophil (PMN) leukocytes are primary phagocytic cells of the bovine mammary gland and a first line of defense against invading pathogens during bovine mastitis infection. Cluster of differentiation 14 (CD14) is mainly expressed in macrophages and neutrophils and acts as a co-receptor that binds bacterial lipopolysaccharide (LPS) and recruits PMNs to CD14-LPS complexes in mammary epithelial cells. In this study, we identified a novel splice variant in PMNs, named CD14-SV, characterized by a deleted region from c.143-579 nt compared to the CD14 reference mRNA sequence. Moreover, a single nucleotide polymorphism (c.523 A>G) in exon 2 of CD14 was identified and found to modify the secondary structure and hydrophilicity of the CD14 protein. Association analysis also showed that the milk somatic cell score, an indicator of mastitis, of cows with the GG genotype was lower than that of cows with the AA and AG genotypes. Our findings suggest that the expression of CD14 in bovine blood PMNs is regulated by alternative splicing, and that CD14-SV is a candidate functional marker that may influence mastitis-resistance in dairy cows.
Assuntos
Bovinos/genética , Receptores de Lipopolissacarídeos/genética , Mastite Bovina/genética , Neutrófilos/metabolismo , RNA Mensageiro/genética , Processamento Alternativo , Animais , Feminino , Variação Genética , Receptores de Lipopolissacarídeos/metabolismo , Masculino , Mastite Bovina/sangue , Polimorfismo de Nucleotídeo Único , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , RNA Mensageiro/metabolismoRESUMO
Phospholipase C zeta 1 (PLCζ1), which transcribes a key protein, has an important function in oocyte activation and embryo development because PLCζ1 can trigger a series of intracellular Ca2+ oscillations in mammals. In this study, a novel splice variant in the testis tissues of adult and fetal Chinese Holstein bulls was characterized by reverse transcription-polymerase chain reaction (RT-PCR) and sequencing analysis. The novel splice variant PLCζ1-sv1 was derived from the PLCζ1 complete transcript (PLCζ1-complete) by alternative splicing; the alternative splicing pattern exhibited alternative 5'-splice sites. The full-length transcript, PLCζ1-complete, is the main transcript found in fetal and adult cow testis tissue. Quantitative real-time PCR (qPCR) analysis demonstrated that the expression levels of the PLCζ1-complete transcript were significantly higher than those of the PLCζ1-sv1 splice variant in bovine testis tissues. PLCζ1 protein sequencing analysis showed that the amino acids at positions 453 to 457 were deleted in PLCζ1-sv1, thereby terminating transcription prematurely. In summary, this study provided information to elucidate the structure and function of the bovine PLCζ1 gene.
Assuntos
Processamento Alternativo/genética , Fosfolipase C gama/genética , Testículo/enzimologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Bovinos , China , Elementos Facilitadores Genéticos/genética , Éxons/genética , Masculino , Dados de Sequência Molecular , Motivos de Nucleotídeos/genética , Fosfolipase C gama/química , Estrutura Terciária de Proteína , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transcrição GênicaRESUMO
Phosphoenolpyruvate carboxykinase 1 (PCK1), also named PEPCK-C, is a multiple-function gene that is involved in gluconeogenesis, glyceroneogenesis, reproduction, female fertility, and development of obesity and diabetes. How its many functions are regulated was largely unknown. Therefore, we investigated mRNA expression and possible splice variants of PCK1 by screening cDNA in nine tissues from Holstein bulls and cows. PCK1 mRNA was highly expressed in the liver, kidney, ovary and testis; expression levels were low in the heart, spleen, and lung tissues. Expression of this gene was not detected in skeletal muscle. This led to the discovery of five novel bovine splice variants, named PCK1-AS1-PCK1-AS5. In PCK1-AS1, 51 nucleotides in the interior of exon 2 were spliced out. In PCK1-AS2, exons 2 and 3 were altered by the alternative 3' and 5' splice sites, respectively. PCK1-AS3 was truncated from the 3' end of exon 2 to the 5' end of exon 4. In PCK1-AS4, exon 5 was completely spliced out. In PCK1-AS5, exons 5 and 6 and the 5' end of exon 7 were spliced out. These splice variants (PCK1-AS1-PCK1-AS5) potentially encoded shorter proteins (605, 546, 373, 246 and 274 amino acids, respectively), when compared to the complete protein (622 amino acids). Considering the functional domains of the PCK1 protein, it is likely that these splice variants considerably affect the function of this protein; alternative splicing could be one of the mechanisms by which the diverse functions of PCK1 are regulated.
Assuntos
Bovinos/genética , Fosfoenolpiruvato Carboxilase/genética , Sequência de Aminoácidos , Animais , China , Clonagem Molecular , DNA Complementar , Éxons , Feminino , Masculino , Dados de Sequência Molecular , Músculo Esquelético/metabolismo , Fosfoenolpiruvato Carboxilase/metabolismo , Conformação Proteica , RNA/genética , Splicing de RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Análise de Sequência de DNARESUMO
Mastitis is an economically devastating disease affecting the dairy industry. Dairy cows with mastitis give reduced milk yield and produce milk that is unfit for consumption. The chemokine receptor CXCR1 is an excellent prospective genetic marker for mastitis resistance in cattle because it regulates neutrophil migration, killing, and survival during infection. We detected 4 single nucleotide polymorphisms (SNPs) of the CXCR1 gene in Chinese native cattle and analyzed their associations with milk traits. Screening for genetic variations in CXCR1 among 648 Chinese Holstein, Luxi Yellow, and Bohai Black cattle by created restriction site polymerase chain reaction (PCR), nested PCR, and DNA sequencing revealed 4 new SNPs with allelic frequencies ranging from 0.676 to 0.821, 0.706 to 0.803, 0.647 to 0.824, and 0.558 to 0.581. All four CXCR1 gene SNPs were located in exon II. Two SNPs, c.337A>G and c.365C>T, were nonsynonymous mutations [ATC (Ile) > GTC (Val) and GCC (Ala) > GTC (Val)], whereas two, c.291C>T and c.333C>T, were synonymous mutations [TTC (Gly) > TTT (Gly) and GGC (Phe) > GGT (Phe)]. Statistical analyses revealed the significant association of c.337A>G and c.365C>T with the somatic cell score, which suggests the possible role of these SNPs in the host response against mastitis. Our data suggest that combined genotypes CCAC/CCGC, CCAC/CTAT, and CCAT/CTAT (lowest somatic cell scores); CTAC/CTAT (highest protein rate); CCAC/CTGC (highest fat rate); and CCAT/CTAT (highest 305-day milk yield) can be used as possible candidates for marker-assisted selection in dairy cattle breeding programs.
Assuntos
Bovinos/genética , Lactação/genética , Polimorfismo de Nucleotídeo Único , Receptores de Interleucina-8A/genética , Animais , Animais Endogâmicos , Éxons , Feminino , Estudos de Associação Genética , Mastite Bovina/genética , Leite/metabolismo , Mutação , Característica Quantitativa HerdávelRESUMO
The mannan-binding lectin gene (MBL) participates as an opsonin in the innate immune system of mammals, and single nucleotide polymorphisms (SNPs) in MBL cause various immune dysfunctions. In this study, we detected SNPs in MBL2 at exon 1 using polymerase chain reaction single-strand conformation polymorphism analysis and DNA sequencing techniques in 825 Chinese Holstein cows. Four new SNPs with various allele frequencies were also found. The g.1164 G>A SNP was predicted to substitute arginine with glutamine at the N-terminus of the cysteine-rich domain. In the collagen-like domain, SNPs g.1197 C>A and g.1198 G>A changed proline to glutamine, whereas SNP g.1207 T>C was identified as a synonymous mutation. Correlation analysis showed that the g.1197 C>A marker was significantly correlated to somatic cell score (SCS), and the g.1164 G>A locus had significant effects on SCS, fat content, and protein content (P < 0.05), suggesting possible roles of these SNPs in the host response against mastitis. Nine haplotypes and nine haplotype pairs corresponding to the loci of the 4 novel SNPs were found in Chinese Holsteins. Haplotype pairs MM, MN, and BQ were correlated with the lowest SCS; MN with the highest protein yield; MM with the highest protein rate, and MN with the highest 305- day milk yield. Thus, MM, MN, and BQ are possible candidates for marker-assisted selection in dairy cattle breeding programs.
Assuntos
Bovinos/genética , Estudos de Associação Genética , Lectina de Ligação a Manose/genética , Leite/metabolismo , Polimorfismo de Nucleotídeo Único/genética , Característica Quantitativa Herdável , Alelos , Sequência de Aminoácidos , Animais , Sequência de Bases , China , Éxons/genética , Frequência do Gene/genética , Haplótipos/genética , Heterozigoto , Análise dos Mínimos Quadrados , Lectina de Ligação a Manose/química , Dados de Sequência Molecular , Polimorfismo Conformacional de Fita Simples/genética , Análise de Sequência de DNA , Coloração pela PrataRESUMO
The complement system helps in the direct lysis of invading pathogens and modulates phagocytic, humoral and cellular immune responses. Complement 4 is a critical component in complement activity and protection against many bacterial pathogens because it is essential to classical and lectin activation pathways. We used reverse transcription and PCR to investigate alternative splicing and expression of the complement component 4 (C4A) gene in Chinese Holstein cattle. The PCR products were cloned and sequenced. A novel splice variant involving intron 10 was identified, which we named C4A-AS. To examine how C4A gene activity is affected by bovine mastitis, six Chinese Holstein cattle were divided into healthy (non-mastitic) and Staphylococcus aureus-induced mastitic groups. Real-time quantitative PCR (qRT-PCR) revealed that the C4A-complete and C4A-AS transcripts are expressed at significantly different levels in healthy cows, while there were no significant differences in the mastitic group (P = 0.257). Expression of C4A-AS increased significantly when mastitis developed. We also examined the expression of C4A-complete and C4A-AS in several tissues (liver, heart, spleen, lung, kidney, tongue, and muscle). The two transcripts were expressed in all of these tissues but there were no significant differences in expression between healthy and mastitic cows. We therefore conclude that the C4A-complete transcript is the main transcript under normal physiological conditions, while C4A-AS is augmented when mastitis develops.
Assuntos
Processamento Alternativo/genética , Bovinos/genética , Bovinos/imunologia , Complemento C4a/genética , Indústria de Laticínios , Mastite Bovina/genética , Mastite Bovina/imunologia , Animais , China , Feminino , Mastite Bovina/microbiologia , Dados de Sequência Molecular , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Staphylococcus aureus/fisiologiaRESUMO
Bovine lactoferrin (bLF) is a member of the transferrin family; it plays an important role in the innate immune response. We identified novel splice variants of the bLF gene in mastitis-infected and healthy cows. Reverse transcription-polymerase chain reaction (RT-PCR) and clone sequencing analysis were used to screen the splice variants of the bLF gene in the mammary gland, spleen and liver tissues. One main transcript corresponding to the bLF reference sequence was found in three tissues in both healthy and mastitis-infected cows. Quantitative real-time PCR analysis showed that the expression levels of the LF gene's main transcript were not significantly different in tissues from healthy versus mastitis-infected cows. However, the new splice variant, LF-AS2, which has the exon-skipping alternative splicing pattern, was only identified in mammary glands infected with Staphylococcus aureus. Sequencing analysis showed that the new splice variant was 251 bp in length, including exon 1, part of exon 2, part of exon 16, and exon 17. We conclude that bLF may play a role in resistance to mastitis through alternative splicing mechanisms.
Assuntos
Lactoferrina/genética , Glândulas Mamárias Animais/imunologia , Mastite Bovina/metabolismo , Infecções Estafilocócicas/veterinária , Staphylococcus aureus/genética , Processamento Alternativo , Animais , Bovinos , Éxons , Feminino , Expressão Gênica , Lactoferrina/imunologia , Lactoferrina/metabolismo , Fígado/imunologia , Fígado/metabolismo , Glândulas Mamárias Animais/metabolismo , Glândulas Mamárias Animais/microbiologia , Mastite Bovina/imunologia , Mastite Bovina/microbiologia , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Baço/imunologia , Baço/metabolismo , Infecções Estafilocócicas/imunologia , Infecções Estafilocócicas/metabolismo , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/imunologiaRESUMO
Transferrin (Tf) is a ß-globulin protein that transports iron ions in mammalian cells. It contributes to innate immunity to microbial pathogens, primarily by limiting microbial access to iron. Thus, polymorphisms present in bovine Tf could potentially underlie inherited differences in mastitis resistance and milk production traits. We detected three novel single-nucleotide polymorphisms of the Tf gene in Chinese native cattle by screening for genetic variation of Tf in 751 individuals of three Chinese cattle breeds, namely China Holstein, Luxi Yellow and Bohai Black, using PCR-RFLP and DNA sequencing techniques. The three new SNPs, g.-1748G>A ss250608649, g.13942T>C ss250608650, and g.14037A>G ss250608651, had allele frequencies of 85.9, 86.3 and 92.5%, 64.5, 73.3 and 65.0%, and 67.6, 73.7 and 60.0%, respectively. SNP g.-1748G>A was located in the 5' flanking region of Tf. SNP g.14037A>G was located in intron 8 of Tf. SNP g.13942T>C, located in exon 8 of Tf, was a synonymous mutation (TTA > CTA), encoding a leucine (326 aa) in the Tf protein. Associations of the Tf SNPs with milk traits were also analyzed. Significant (P < 0.05) relationships among the Tf polymorphisms, somatic cell scores (SCS), and milk productive traits were observed. Cows with genotypes TT (g.13942T>C), GG (g.-1748G>A) and AG (g.14037A>G) had a lower SCS and higher protein levels and 305-day milk yield. Nineteen combinations of different haplotypes from the three SNPs were identified in Chinese Holstein cattle. The haplotype combination ATA/GCA, GCA/GCA and GCG/ GTA was dominant in cows with a lower SCS, a higher protein level and a higher 305-day milk yield, respectively. Moreover, the gene expression level of Tf was higher in mastitis-affected mammary tissues than in normal mammary tissues. These results suggest that the Tf gene affects milk production, as well as mastitis-resistance traits, in Chinese Holsteins.