Polymerase Chain Reaction-single Strand Conformation Polymorphism Research Articles

Diplotype-based assessment of GNRHR gene polymorphisms and their role in determining litter size at birth in the Malabari goat population of South India

The Gonadotropin Releasing Hormone Receptor (GNRHR) gene, a key regulator of the hypothalamo-pituitary-gonadal axis, plays a pivotal role in modulating reproductive potential in mammals by influencing the release of gonadotropins. In this study, we conducted a comprehensive population genetic analysis of haplotypes and diplotypes of the GNRHR and explored their association with litter size at birth in the prolific Malabari goat breed of South India. Utilizing PCR-single strand conformation polymorphism (SSCP) and PCR-sequencing-based typing (SBT) techniques, we genotyped 185 Malabari goats for diplotypes encompassing specific single nucleotide polymorphisms (SNPs) at c.–33A>G, c.–29 T>G, c.48 G>A, c.75 G>A, and c.209 T>G loci of the GNRHR gene. The PCR-SSCP and PCR-SBT revealed the presence of seven diplotypes and six haplotypes within the study population. Our results, as determined by ordinal logistic regression analysis, demonstrated a highly significant (p<0.01) influence of GNRHR diplotypes on litter size at birth up to the third parity, with a significant (p<0.05) effect observed in the fourth parity in Malabari goats. Specifically, the odds of multiple births were found to be 53.3% and 80.7% higher for AGAGG/ATGGT diplotypes compared to AGAGG/AGAGG diplotypes in the first and second parity, respectively. Furthermore, the odds ratio analysis highlighted a higher percentage of multiple births in AGAGG/AGAAG diplotypes during the third and fourth parities compared to other diplotypes in Malabari goats. Collectively, our findings suggest that heterozygote diplotypes confer a reproductive advantage over homozygous diplotypes for litter size at birth in the Malabari goat breed.

Genetic Characterization of Myf5 and POU1F1 Genes in Different Egyptian Local Rabbit Breeds and Their Association with Growth Traits.

Genetic characterization and its association with quantitative traits in local breeds are important tools for the genetic improvement and sustainable management of animal genetic resources. Myogenic regulatory factor 5 (MYf5) and POU class 1 homeobox 1 (POU1F1) are candidate genes which play important roles in growth and development of mammals. The present study aims to detect the genetic diversity of the MYf5 and POU1F1 genes in four local Egyptian rabbit breeds and their association with growth traits, using PCR-restriction enzyme (PCR-RFLP), PCR-single-strand conformational polymorphism (PCR-SSCP), and direct sequencing techniques. The results showed that MYF5 exon 1 was observed with two genotypes in Baladi Black (BB), Gabali (GB) and New Zealand White (NZW) breeds while APRI-line (APRI) presented one genotype. The genetic diversity of Myf5 exon 2 between breeds showed two genotypes in APRI compared to three in NZW and four genotypes in BB and GB breeds. The genetic diversity of the POU1F1 gene (intron 5 and partial cds) in different rabbit breeds was two genotypes in NZW and three genotypes in BB, GB, and APRI breeds with different frequencies for each genotype. Based on the statistically significant difference between genes genotypes and growth weight, the results suggested that the genotypes of Myf5 exon 2 (1 and 2) of the BB breed, Myf5 exon 2 genotype 2 of the APRI breed, and genotype 1 of Myf5 exon 1 and genotype 1 of POU1F1 of the NZW breed compared to genotypes for each gene can be considered candidate molecular markers associated with the improvement of growth traits in these breeds.

Correlation analysis between polymorphism of leptin and IGFI genes and body measurements in Barki and Farafra sheep

BackgroundGrowth performance, which can be evaluated using various body measurements, is crucial for providing red meat for human consumption. This study aims to improve the growth performance of sheep by identifying the different genotypes of leptin and IGFI genes associated with higher body measurements.MethodsIn this study, we collected blood samples from Barki (n = 30) and Farafra (n = 30) sheep, and measured their body height, width, length, and weight, and tail width and length to assess their growth performance. We used single strand conformation polymorphism polymerase chain reaction (SSCP-PCR) and sequencing analysis to identify single nucleotide polymorphisms (SNPs) and different genotypes of the leptin and insulin-like growth factor receptor (IGFI) genes associated with sheep body measurements.ResultsThe leptin gene (209 bp) and IGFR gene (345 bp) were found to have three (TT, TG, and GG) and (TT, TC, and CC) genotypes, respectively, by SSCP-PCR. Sequence analysis revealed a SNP in the leptin gene (200G > T) with two alleles (G allele: OR058867 and T allele: OR058868). This SNP resulted in the substitution of the amino acid valine with leucine, which increased the width, length, and weight of the body and tail width in the heterozygous form (TG). The IGFI gene had three SNPs: 305 G > T in TT genotype (OR260670), 184C > T, 265T > C, and 305G > T in TC genotype (OR260669), and 265T > C in CC genotype (OR260671). The TC genotype of the IGFR gene was correlated with higher values of body measurements. Barki sheep were found to have the highest values for body weight, width, length, and tail width compared to Farafra sheep.ConclusionWe recommend the use of entire Barki sheep in inbreeding programs to improve growth performance in Egyptian sheep.

Identification of the Keratin-Associated Protein 22-2 Gene in the Capra hircus and Association of Its Variation with Cashmere Traits.

The Cashmere goat is an excellent local goat breed in Gansu Province of China, and it is expected to improve cashmere production and cashmere quality through selection and breeding to enhance its commercial value. Keratin-associated proteins (KAPs) play an important role in maintaining wool structure. The gene encoding the keratin-associated protein 22-2 (KAP22-2) gene has been identified in selected species other than goats, such as humans, mice, and sheep. In this study, the sequence of the sheep KAP22-2 gene (KRTAP22-2) was aligned into the goat genome, and the sequence with the highest homology was assumed to be the goat KRTAP22-2 sequence and used to design primers to amplify the goat gene sequence. A total of 356 Longdong Cashmere goats (Gansu Province, China) were used for screening of genetic variants. Four specific bands were detected by polymerase chain reaction-single-stranded conformational polymorphism (PCR-SSCP) analysis, and they formed a total of six band types individually or in combination. Four alleles were identified by DNA sequencing of PCR amplification products. A total of four single nucleotide polymorphic sites (SNPs) were detected in the four sequenced KRTAP22-2 alleles. Two of them are in the 5'UTR region and the other two are in the coding region, and the variants in the coding region are all non-synonymous mutations. In addition, there was a 6 bp length variation in allele C. The gene was expressed in the cortical layer of primary and secondary hair follicles, the inner root sheath, as well as hair papillae and hair maternal cells in goats. The results of the correlation analysis between genotypes and cashmere traits showed that after excluding genotypes with a gene frequency of less than 5%, the mean fiber diameter (MFD) of cashmere was significantly higher in the AB genotype than in the AA and AC genotypes. That is, the KRTAP22-2 gene variants are associated with mean fiber diameter in cashmere. The above results suggest that the goat KRTAP22-2 variant can be utilized as a molecular marker candidate gene for cashmere traits.

Chronic or recurrent Campylobacter enteritis in primary immunodeficiency: a UK national case-series and review of the literature.

Chronic or recurrent Campylobacter enteritis in primary immunodeficiency: a UK national case-series and review of the literature.

A Novel Missense SNP in the Fatty Acid-Binding Protein 4 (FABP4) Gene is Associated with Growth Traits in Karakul and Awassi Sheep.

The fatty acid-binding protein 4 (FABP4) plays a crucial role in the transportation and metabolism of fatty acids. It binds to long-chain fatty acids and facilitates their transport within cells. FABP4 is involved in lipid metabolism, insulin sensitivity, inflammation, and energy homeostasis. This study was conducted to assess the association between the FABP4 gene and growth traits in Karakul and Awassi sheep. A PCR-single strand conformation polymorphism (SSCP) protocol was utilized to assess the polymorphism of FABP4 PCR products with growth traits measured at birth, three, six, nine, and twelve-month intervals. One non-synonymous SNP was identified in the second exon, in which threonine was converted to aspartate in the 61st position in FABP4 (p.61Thr > Asp). This novel SNP showed significant associations with all growth traits measured at all age intervals. The results showed that lambs with the TT genotype exhibited higher growth traits than those with the GT and GG genotypes, respectively. The conducted prediction showed a clearly deleterious effect of p.61Thr > Asp on FABP4 structure, which was accompanied by reduced fatty acid binding efficiency. Owing to the predicted damaging effects caused by p.61Thr > Asp on FABP, lower levels of lipid transport and its consequent increased weight gain and other growth trait indices are expected. Therefore, a putative mechanism through which lambs with these genotypes exhibit higher growth traits is proposed. The FABP4 gene is suggested as apromising markerto improve growth traits in Karakul and Awassi sheep. However, more research is required to validate this mechanism.

Polymorphic Variants Analysis in Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-Alpha (PPARGC1A) Gene of Indian and Egyptian Buffaloes

Background-Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PPARGC1A) is a candidate gene for milk fat in livestock. The present study was carried out to investigate polymorphism in PPARGC1A and study its potential association. Methods-Two hundred forty animals from Murrah and Bhadawari Indian buffalo breeds and Egyptian buffaloes were selected. The statistical analysis used Tukey’s honest significance test to investigate the association of different genotypes. PCR-SSCP (polymerase chain reaction-single strand conformation polymorphism) assays and sequencing technologies were used to confirm the SNPs. Results-Three Novel single nucleotide polymorphisms (SNP1- g.993A greater than T, SNP2- g.1237T greater than A and SNP3-g.1238G greater than C) and one insertion (g.1240_ greater than G bp) were identified in this gene. Due to nucleotide mutations, four non-synonymous mutations were observed amino acid sequences of buffalo breeds. Significant differences in protein and SNF output were discovered in Egyptian buffalo breeds. In both Murrah and Bhadawari buffaloes, fat, protein, and SNF yield were substantially correlated with detected genotypes while there was non-significant association of protein and SNF percent in buffalo breeds. The information provided will be valuable in studying the involvement of PPARGC1A in regulating fat synthesis and enhancing milk quality in buffaloes.

The identification of a novel SNP in the resistin (RETN) gene associated with growth traits in Karakul and Awassi sheep

Resistin is one of the most important adipocytokines in mammalian cells due to its involvement in insulin resistance, obesity, and autoimmune diseases. Resistin is encoded by RETN gene that is primarily expressed in adipose tissues. Mutations in this gene have been associated with several productive traits in animals. This study was conducted to assess the possible biomarker capacity of RETN by evaluating its association with growth traits in two economically important sheep in the Middle East. Genotyping was conducted using PCR-single strand conformation polymorphism (SSCP), and the polymorphism of RETN was associated with several growth traits for three months intervals starting from birth until one year of age. In a total of 190 Karakul sheep and 245 Awassi sheep, only one SNP (233A > C) was detected in the RETN gene. The identified novel SNP showed significant associations with all growth traits at the ages of six, nine, and twelve months. At the age of six months onward, lambs with AC and CC genotypes showed respectively lower body weight and length, chest and abdominal circumferences, and wither and rump heights than those with AA genotype. Dueto the remarkable association between RETN;233A > C and lower growth traits, this genotype is suggested as apromising markerto assess growth traits in Karakul and Awassi sheep. This is the first study that demonstrated the importance of RETN as a possible tool for evaluating growth traits in two breeds of sheep with a possibility to be applied to other breeds via large-scale association analysis.

A missense SNP in the proopiomelanocortin (POMC) gene is associated with growth traits in Awassi and Karakul sheep

This study was conducted to assess the association between proopiomelanocortin (POMC) gene and growth traits in Awassi and Karakul sheep. PCR-single strand conformation polymorphism (SSCP) method was utilized to assess the polymorphism of POMC PCR amplicons with body weight and length, wither and rump height, chest and abdominal circumference measured at birth, 3, 6, 9, and 12 months intervals. Only one missense SNP (rs424417456:C > A) was detected in exon-2, in which glycine was converted to cysteine in the 65th position in POMC (p.65Gly > Cys). rs424417456 SNP showed significant associations with all growth traits in the third, sixth, ninth, and twelfth months. At the age of 3 months onward, lambs with CC genotype showed higher body weight, body length, wither and rump heights, and chest and abdominal circumferences than lambs with CA and AA genotypes, respectively. Prediction analyses indicated a deleterious effect of p.65Gly > Cys on POMC structure, function, and stability. Owing to the strong correlation between rs424417456:CC and better growth characteristics, this genotype is proposed as a promising marker to enhance growth traits in Awassi and Karakul sheep. The predicted damaging effects caused by rs424417456:CA and rs424417456:AA genotypes may entail a putative mechanism through which lambs with these genotypes exhibit lower growth traits.

Polimorfismo dos genes DGAT e LEP e sua associação com características de carcaça e perfil lipídico da carne de bovinos nelore

ABSTRACT The objective of this study was to evaluate the association of polymorphisms in the diacylglycerol acyltransferase ( DGAT ) and leptin ( LEP ) genes with the performance, carcass characteristics, meat quality, and lipid profile of Nellore cattle. A total of 100 intact male Nelore cattle were used to analyze the performance, carcass, physicochemical and centesimal composition, and fatty acid profile of beef. To identify the polymorphisms, the PCR–single-strand conformation polymorphism (SSCP) technique was applied to genomic DNA extracted from muscle tissue. The SSCP technique revealed the presence of four band patterns for the DGAT gene (AC, AD, AE and BB) with five alleles (A, B, C, D and E). For the LEP gene, five band patterns (AA, AB, AC, BB and BC) with three alleles (A, B and C) were observed. For the LEP gene, the AB genotype was associated with higher backfat thickness and ribs weight, while the BB genotype was associated with lower ribs yield; higher hindquarter yield was associated with AC and BB genotypes. Higher contents of C17:0, C18:0 and lower contents of C18:2ω6C, total polyunsaturated fatty acids, total ω6 and ratio of polyunsaturated and saturated fatty acids (PUFA/SFA) were verified for the AC genotype of the LEP gene. The AC and AA genotypes of the LEP gene were associated with higher means of C15:0 and C18:1ω9t. For the DGAT gene, the highest C24:0 content was associated with the AE genotype and the lowest with the AD and BB genotypes. Polymorphisms in the DGAT and LEP genes influence carcass parameters and the lipid profile of the meat of Nellore cattle.

A novel deleterious oxytocin variant is associated with the lower twinning ratio in Awassi ewes

This study aimed to assess the possible association of oxytocin (OXT) gene with reproductive traits in two groups of Awassi ewes that differ in their reproductive potentials. Sheep were genotyped using PCR—single-stranded conformation polymorphism approach. Three genotypes were detected in exon 2, CC, CA, and AA, and a novel SNP was identified with a missense effect on oxytocin (c.188C > A → p.Arg55Leu). A significant (p < 0.01) association of p.Arg55Leu with the twinning rate was found as ewes with AA and CA genotypes exhibited, respectively a lower twinning ratio than those with the wild-type CC genotype. The deleterious impact of p.Arg55Leu was demonstrated by all in silico tools that were utilized to assess the effect of this variant on the structure, function, and stability of oxytocin. Molecular docking showed that p.Arg55Leu caused a dramatic alteration in the binding of oxytocin with its receptor and reduced the number of interacted amino acids between them. Our study suggests that ewes with AA and CA genotypes showed a lower reproductive performance due to the presence of p.Arg55Leu, which caused damaging impacts on oxytocin and is binding with the OXT receptor. The utilization of the p.Arg55Leu could be useful for improving Awassi reproductive potential.

Expression and Variations in EPAS1 Associated with Oxygen Metabolism in Sheep.

Endothelial PAS domain protein 1 gene (EPAS1) is a member of the HIF gene family. This gene encodes a transcription factor subunit that is involved in the induction of oxygen-regulated genes. Several studies have demonstrated that a mutation in EPAS1 could affect oxygen sensing, polycythemia, and hemoglobin level. However, whether EPAS1 mutation affects sheep oxygen metabolism is still unknown. Therefore, we explored the relationship between the variation of EPAS1 and oxygen metabolism in sheep. In this study, variations in ovine EPAS1 exon 15 were investigated in 332 Tibetan sheep and 339 Hu sheep by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis. In addition, we studied the effect of these variations on blood gas in 176 Tibetan sheep and 231 Hu sheep. Finally, the mRNA expression of EPAS1 in six tissues of Hu sheep and Tibetan sheep living at different altitudes (2500 m, 3500 m, and 4500 m) was analyzed by real-time quantitative PCR (RT-qPCR). Four alleles (A, B, C, and D) were detected, and their distributions highly differed between Tibetan sheep and Hu sheep. In Tibetan sheep, B was the dominant allele, and C and D alleles were rare, whereas all four alleles were common in Hu sheep. Six single nucleotide polymorphisms (SNPs) were identified between the four alleles and one of them was non-synonymous (p.F606L). While studying the blood gas levels in Tibetan sheep and Hu sheep, one variant region was found to be associated with an elevated pO2 and sO2, which suggested that variations in EPAS1 are associated with oxygen metabolism in sheep. RT-qPCR results showed that EPAS1 was expressed in the six tissues of Hu sheep and Tibetan sheep at different altitudes. In addition, the expression of EPAS1 in four tissues (heart, liver, spleen, and longissimus dorsi muscle) of Hu sheep was lower than that in Tibetan sheep from three different altitudes, and the expression of EPAS1 was positively correlated with the altitude. These results indicate that the variations and expression of EPAS1 is closely related to oxygen metabolism.

Variation in Ovine DGAT1 and Its Association with Carcass Muscle Traits in Southdown Sheep.

Diacylglycerol O-acyltransferase 1 (DGAT1) is a microsomal enzyme that plays a key role in the synthesis of triglycerides. Its gene (DGAT1) is regarded as a candidate gene for variation in milk and meat traits in cattle. The objective of this study was to use a PCR single-strand conformation polymorphism approach to explore sequence variation in two regions of ovine DGAT1 and to assess its effect on meat traits in New Zealand Southdown sheep. Three variant nucleotide sequences were identified in each region, with two single nucleotide polymorphisms (SNPs) and one nucleotide deletion being detected in intron 1 and two SNPs being found in exon 17. The effect of the exon 17 variation was not investigated due to one variant being predominant and the other two variants occurring at low frequencies. In intron 1, one variant (B1) was found to be associated with increase loin meat yield, suggesting that this may have value as a gene marker for improving meat traits.

Identification of the KAP27-1 gene in sheep and its effect on wool traits

ABSTRACT The keratin-associated proteins (KAPs) are structural components of wool and hair fibres, with over 90 genes that encode these proteins having been identified in mammalian species. A KAP gene called KRTAP27-1 was recently identified in goats, but the gene has not been reported in the closely related ruminant species sheep. In this study, we used a polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis to find ovine KRTAP27-1 and investigate nucleotide sequence variation in the gene. Our analysis revealed four sequence variants (named A to D) in 399 New Zealand Merino × Southdown-cross sheep. Within these sequence variants there were five single nucleotide polymorphisms (SNPs) in the coding region, including two non-synonymous SNPs. Six genotypes (AA, AB, AC, BB, BC and BD) of KRTAP27-1 were detected, and for the three genotypes with a frequency of over 5.0%, sheep of genotypes AB and BB produced wool of higher mean staple length (MSL) and higher greasy fleece weight (GFW) than sheep of genotype AA. These results suggest that variation in ovine KRTAP27-1 may be affecting wool growth and thus production.

Variants of the SCD gene and their association with fatty acid composition in Awassi sheep.

Genetic factors affect the variability of fatty acid composition in ruminant products. Thus, this study aimed to investigate the association between the variations of the SCD gene and fatty acid composition in Awassi sheep. A total of 100 Awassi rams between the ages of one and two and a half years old were used in this study. Blood samples were taken at abattoirs in Babylon, and from each animal, longissimus dorsi (LD) muscle samples were taken to measure the fatty acid composition. DNA samples were isolated from each blood sample, then PCR-single strand conformation polymorphism (PCR-SSCP) experiments were conducted for genotyping followed by sequencing reactions. The study identified two genotypes (TT and TA) of the SCD gene (exon 3). Several novel variants were discovered in the amplified fragments of the SCD gene. The TA genotype resulted in increased intramuscular fat and monounsaturated fatty acids compared to the TT genotype. Breeding for the TA genotype could be used for producing meat containing less saturated fatty acids and more monounsaturated fatty acids, making meat more favorable for human consumption.

Major Histocompatibility Complex (MHC) Diversity of the Reintroduction Populations of Endangered Przewalski's Horse.

Major histocompatibility complex (MHC) genes are the most polymorphic in vertebrates and the high variability in many MHC genes is thought to play a crucial role in pathogen recognition. The MHC class II locus DQA polymorphism was analyzed in the endangered Przewalski’s horse, Equus przewalskii, a species that has been extinct in the wild and all the current living individuals descend from 12 founders. We used the polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) to detect the polymorphism within the MHC DQA in 31 Przewalski’s horses from two reintroduced populations. Consequently, only seven alleles were identified, with only four presenting in each population. In comparison with other mammals, the Przewalski’s horse demonstrated less MHC variation. The nucleotide genetic distance of the seven ELA-DQA alleles was between 0.012 and 0.161. The Poisson corrected amino acid genetic distance of the founded alleles was 0.01–0.334. The allele and genotype frequencies of both reintroduced populations of Przewalski’s horse deviated from the Hardy–Weinberg equilibrium. Specific MHC DQA alleles may have been lost during the extreme bottleneck event that this species underwent throughout history. We suggest the necessity to detect the genetic background of individuals prior to performing the reintroduction project.

Artificial Neural Network-Based Identification of Associations between UCP2 and UCP3 Gene Polymorphisms and Meat Quantity Traits

In identifying mutations occurring in distinct cow breeds, genetic elements must be taken into consideration. More recently, these hereditary features have gained attention throughout the world. As in many underdeveloped nations, to bridge the deficit in molecular genetics, multiple solutions are required. The inner membrane anion carrier superfamily contains the uncoupling proteins (UCPs), vital to energy regulation. Research on heredity has shown that variations in the UCP2 and UCP3 genes are connected to obesity and metabolic syndrome. This research aimed to investigate if any mutation in the UCP 2 and UCP 3 genes are related to many characteristics in Pakistan’s three indigenous cattle breeds using artificial neural network (ANN). For better analysis, the output of the ANN model is loaded into the Primer Premier 3 software. Using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and sequencing, the results of this study indicated 07 variations in the exon 4 region of the UCP2 gene and 03 variants in the exon 3 area of the UCP3 gene among 215 indigenous cow breeds. The association study revealed that the g.C35G mutation in the UCP3 gene is strongly related to meat quantity characteristics such as carcass weight and drip percentage (P0.05) but not with body height or hip width ( P &gt; 0.05 ). Sequence analysis showed five distinct diplotypes: AA, BC, AC, CC, and CD. Cattle with the novel heterozygous diplotype BC perform better in carcass trait and drip percentage than animals with other genotypes. The study’s findings suggest that the UCP3 gene may be utilized for marker-assisted selection (MAS) and breed mixing in Pakistan cattle breeds to aid in the country’s economic growth.

Correlation of lipoprotein lipase gene polymorphism and mRNA expression with intramuscular fat content in Baicheng-Oil chicken.

Lipoprotein lipase (LPL) was often taken as a candidate gene for investigating fat metabolism. However, there are few studies on the effect of LPL on intramuscular fat (IMF) deposition in Baicheng oil chicken (BOC) and Three-yellow Chicken (TYC). In this study, we studied the relationship between polymorphism and messenger RNA (mRNA) expression of LPL with IMF deposition in the chest muscle (CM) and leg muscle (LM) of TYC and BOC. Sixty TYCs and 60 BOCs were raised from 1 d and slaughtered by avascularization at their slaughtering age. IMF contents of the CM and LM in the BOC were markedly higher than those in the TYC. Three genotypes following AA, AB and BB were found by the method of polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP). The synonymous mutation C12315T was detected. The content of IMF with the AA genotype was significantly higher than the AB genotype in the LM of TYC. The mRNA expression both of CM and LM in BOC was prominently higher than those in TYC, and there was a positive significant correlation between LM and CM in both BOC and TYC. These results suggested that the SNPs polymorphism and mRNA expression of the LPL gene might be helpful for selective breeding in IMF of the chicken.

Variation in caprine KRTAP1-3 and its association with cashmere fibre diameter

Keratin-associated proteins (KAPs) are components of cashmere fibres. The gene encoding the KAP1-3 protein (KRTAP1-3) has been described in goats, but little is known about sequence variation in this gene and if it affects cashmere fibre traits. In this study, we used a polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) technique to screen for nucleotide sequence variation in caprine KRTAP1-3 in 327 Longdong cashmere goats, then analysed association between the genetic variation that was revealed and some cashmere fibre traits. Six PCR-SSCP patterns representing six different variant sequences of KRTAP1-3 (named A to F) were revealed. Among these variant sequences, seven single nucleotide polymorphisms (SNPs) were detected, with two of them being non-synonymous. Goats with genotype AC had higher mean fibre diameter (MFD) than those with genotype AB (P < 0.001), while goats with genotype AB had higher MFD than those with AA (P < 0.001). The presence of C (P < 0.001) and B (P = 0.006) in a genotype was associated with increased MFD, and together this suggests that variation in caprine KRTAP1-3 affects the key fibre trait of MFD.

Association of a single nucleotide polymorphism of the Leptin gene with growth traits in Takifugu rubripes

Leptin (LEP) plays a role in animal growth, appetite regulation, energy partition, and body composition. In this study, 296 cultivated Takifugu rubripes individuals were screened for LEP gene polymorphisms using PCR-single strand conformation polymorphism (PCR-SSCP) and DNA sequencing. Two single nucleotide polymorphism (SNP) mutations were detected in T. rubripes LEP gene: C/G at position 232 nucleotide (nt) and C/T at position 310 nt. One-way ANOVA of the SNPs and growth traits showed that genotype CC of primer L2 had a significantly higher body length (BL), body weight (BW), and absolute growth rate of BL (ABL) and BW (ABW) than genotypes CG and GG (P&lt;0.05). The genotype frequencies of CC, CG, and GG were 61.15%, 35.14%, and 3.17%, respectively. Genotype CC at the C232G site was advantageous and significantly associated with growth traits. This site would be an excellent molecular marker to select and cultivate through statistical analysis. Additionally, the second unmutated and mutated mRNA structures were compared and analyzed. These results indicate that the T. rubripes LEP gene may be a candidate for these growth traits.