Leptin Genotype Research Articles

Association between leptin gene polymorphism and growth traits in Bali cattle

Leptin (LEP) gene produces hormone leptin which is secreted by adipose tissue, and plays an im-portant role in energy balance, regulating feed intake, regulating endocrine function, and immune functions. This study aims to identify molecular markers of LEP gene and its association with growth traits based on SNP in Bali cattle. The blood samples were collected from 16 male and 30 female Bali cattle. The growth data were recorded from 2018 to 2020, consist of body weight and body size. Am-plification of leptin gene with polymerase chain reaction (PCR) using pair of primers, Lep-tin_3Forward: 5’- AGCTTGGAAACATGGTGGTC-3’ and Leptin_3Reverse: 5’- CATGATGCTCCCTGGATTCT-3’ with DNA target 898 bp. The SNPs were identified by the direct sequencing technique. Genotypes of the SNPs were identified using sequencing method. Association of LEP genotypes with growth traits was performed using oneway ANOVA. Three DNA polymor-phisms of the LEP gene were found, namely g.2913C/T, g.3260T/C, and g.3549G/A. SNP g.2913C/T was significantly associated (P<0,05) with weaning shoulder height (WSH), weaning body length (WBL), weaning chest circumference (WCC), yearling shoulder height (YSH), yearling body length (YBL), and yearling chest circumference (YCC). Meanwhile, SNPs g.3260T/C and g.3549G/A were not associated with the body weight and body size in Bali cattle. In conclusion, the SNP g.2913C/T can be used as molecular marker for body size in weaning and yearling of Bali Cattle.

Leptin Gene (T117C) Polymorphism and Its Association with Milk Yield Performance in Crossbred Anglo-Nubian Goats

This study was performed to determine polymorphism in the leptin gene (T117C) and investigate the association between genotypes and milk yield in 101 crossbred Anglo-Nubian dairy goats from Awang, Opol, Misamis Oriental and Talay, Dumaguete City, Negros Oriental in the Philippines. Milk yield performance data were standardized to 90 and 140 d milking periods. The goat’s hair follicles were collected to extract genomic DNA. Polymerase chain reaction– restriction fragment length polymorphism (PCR-RFLP) was the method used in genotyping with NmuCI as the restriction enzyme. Statistical analysis was performed following the two-way factorial (2 x 4) in a randomized complete block design (RCBD), where leptin genotypes and parity were used as main factors and farm as the blocking factor. Two genotypes (TT and TC) were obtained. Genotypic frequencies between TT (0.50) and TC (0.50) were evenly distributed, while allele T (0.75) occurred more frequently than allele C (0.25) in the total population studied. Observed heterozygosity is higher than the expected heterozygosity and the genetic variation observed in the overall population was in Hardy-Weinberg equilibrium (p > 0.05). Milk yield traits at 140 d milking period in crossbred Anglo-Nubian dairy goats were significantly influenced by polymorphisms in leptin (T117C). Goats having TT genotype had superior milk yield performance (140dADMY: 0.90L ± 0.058L, 140dTMP: 124.65L ± 8.51L) than those with TC genotype (140dADMY: 0.78L ± 0.051L, 140dTMP: 107.90L ± 7.21L). Further studies should be conducted in other goat breeds to validate associations of leptin polymorphism with milk production and in other economically important traits.

SNP Association in the Leptin Gene and Beef Quality Traits in Indigenous Sudanese Baggara Cattle

The present study was conducted on 112 Sudanese Baggara bulls (Nyalawi and Mesairi strains) from two separate locations in Darfur and Kordofan, Sudan, raised under dryland farming conditions. A single nucleotide polymorphism (C/T) Arg25Cys in exon 2 of the bovine leptin gene (NC_032653.1) was studied and the association of leptin genotypes with meat quality attributes was evaluated for these two Sudanese Baggara cattle strains which comprise the mainstay of Sudan export and local beef trade. The accuracy of genotyping was checked through PCR-RFLP technique followed by DNA sequencing and analyzed using BioEdit, MEGA6 and project Hope softwares. The genotype frequencies for CC, CT and TT genotypes in Nyalawi strain were 37.5, 39.3 and 23.2%, respectively, whereas the respective genotypic frequencies for Mesairi strain were 46.4, 28.6 and 25%. Significant differences (P<0.05) were found in hot carcass weight, dressing percentage, Myofibril fragmentation index (MFI), water holding capacity (WHC), cooking loss, moisture and fat between the two Baggara cattle strains. Association between the C>T SNP at the leptin gene and carcass weight, dressing and fat percentages was significant (P<0.05). It was concluded that Leptin gene polymorphisms contributed to the observed meat quality differences among these Sudanese cattle strains. This will allow for the use of molecular information in future selection of beef cattle in Sudan. The possible value of the leptin gene and its polymorphisms have been elucidated for the first time in Baggara cattle.

PSV-18 The role of leptin in feed efficiency and behavior attributes of commercial beef heifers

Abstract Leptin is a 16-kDa-peptide hormone product of the leptin gene (LEP) that is predominantly synthesized by adipose tissues and has known involvement in regulation of feed intake, energy expenditure, reproduction, and immune functions. The objective was to determine the association of leptin genotype (LEP c.73C >T), leptin diplotype (LEPD) and plasma leptin hormone (LEPH) concentration with growth, feed intake, feed efficiency, and behavior characteristics in developing beef heifers. A total of 336 commercial beef heifers were genotyped for the LEP c.73C >T marker. Four single nucleotide polymorphism markers including LEP c.73C >T, ARS-BFGL-NGS-59298 (intron 1), BovineHD0400026029 (upstream) and BovineHD0400026063 (downstream) of LEP were considered for haplotype analysis. Eleven LEPD were identified for this study using parsimony-based analyses. Circulating levels of LEPH were measured on 333 heifers prior to their first breeding season and used to assign low or high concentration group based on population median. Data were analyzed using the mixed procedure of SAS for repeated measures, fixed effects of ancestral breed group (n = 4), dam age category (n = 4), frame size group (n = 4), project cycle nested within birth year (n = 6), week of feed trial × year, LEP (n = 3) or LEPD (n = 11) or LEPH (n = 2), as well as week × LEPH (only for LEPH). There were no significant differences between LEP genotypes (P ≥ 0.11) or LEPD (P ≥ 0.33) for any of the studied traits. Heifers with low LEPH ate fewer meals per day (P = 0.02) and had more DMI per meal (P = 0.04) compared to those with high plasma leptin. Further research is needed to better understand plasma LEPH concentration and its role in feeding behavior attributes. However, circulatory LEPH before the breeding season may serve as a predictor for feeding behavior.

Dissimilar regulation of glucose and lipid metabolism by leptin in two strains of gibel carp (Carassius gibelio).

Previous nutritional studies have shown that insulin regulation is different between DT and A strains of gibel carp. As leptin plays a pivotal role in the effects of insulin, we hypothesised that leptin regulation of glucose and lipid metabolism would differ between the two strains. To test our hypothesis, recombinant human leptin was injected into two strains. The results showed that leptin activated the phosphatidylinositol 3-kinase (PI3K)-protein kinase B (AKT), AMP-activated protein kinase-acetyl coenzyme A carboxylase and Janus kinase 2 (JAK2)-signal transducer and activator of transcription (STAT) signalling pathways in both strains. Hypoglycaemia induced by leptin might be due to higher glucose uptake by the liver and muscles together with enhanced glycolytic potential and reduced gluconeogenic potential. Decreased lipogenesis and up-regulated fatty acid oxidation were induced by leptin. In terms of genotype, the PI3K-AKT signalling pathway was more strongly activated by leptin in the muscle tissue of the A strain, as reflected by the heightened phosphorylation of AKT. Furthermore, glycogen content, glycolytic enzyme activity and gluconeogenic capability were higher in the A strain than the DT strain. Strain A had higher levels of fatty acid synthesis and lipolytic capacity in the liver than the DT strain, but the opposite was true in white muscle. Regarding leptin-genotype interactions, the DT strain displayed stronger regulation of glucose metabolism in the liver by leptin as compared with the A strain. Moreover, a more active JAK2-STAT signalling pathway accompanied by enhanced inhibition of fatty acid synthesis by leptin was observed in the DT strain. Overall, the regulation of glucose and lipid metabolism by leptin differed between the two strains, as expected.

Potential protective effect of leptin and uncoupling protein-2 genes polymorphism in Egyptian patients with chronic kidney disease.

Kidney disease is a serious public health problem worldwide. It is the fifth top-ranking cause of death in Egypt, causing approximately 3.98% of all deaths. This study's objective was to examine whether an association exists between leptin (- 2548G/A) and uncoupling protein-2 45bp I/D genes, individually and collectively, in CKD and progression to ESRD. One hundred patients (69 males, 31 females) aged (47.1 ± 16.11years) with ESRD, 40 patients (19 males, 21 females) aged (43.15 ± 10.00years with CKD, and 50 healthy controls (23 males, 27 females) aged (37.84 ± 1.95years) were enrolled. Polymerase chain reaction (PCR) was employed to measure variation in gene expression among the study groups. The frequency of single nucleotide polymorphisms (SNP) genotypes were identified in controls, CKD and ESRD patients. Leptin genotypes were associated with lower CKD incidence in control versus study subjects (95% CI = (0.08-0.63), P = 0.01) with risk value equal to 0.22 < 1, G/A genotype was significantly lower in CKD than ESRD groups. There was no correlation between UCP-2 I/D genotype and CKD (P = 0.27). There was no correlation between the UCP-2 gene and the progression to ESRD. This study suggests that, Leptin - 2548G/A gene may be a promising marker for early detection of ESRD in Egyptian patients. G/A genotype might inhibit the development of CKD to ESRD.

Association of leptin genotype with growth performance, adipocyte cellularity, meat quality, and fatty acid profile in beef steers fed flaxseed or high-oleate sunflower seed diets with or without triticale dried distiller's grains.

Leptin genotypes can be identified as homozygous normal (CC), homozygous mutant (TT), and heterozygous (CT) based on a single-nucleotide polymorphism in exon 2 of the leptin gene, which has been associated with feed intake and fat deposition in cattle. The experiment was designed as 2 × 2 × 2 factorial with three main factors: (1) genotype (CT or TT) and diets fed 2) with or without triticale dried distiller's grains with solubles (DDG), and 3) with either flaxseed (FS) or high-oleate sunflower seed (SS). Evaluations included growth performance, subcutaneous fat deposition, adipocyte cellularity, meat quality, and fatty acid (FA) profile of various depots. Beef steers (n = 40, 459 ± 31 kg) of either CT or TT genotypes were housed in individual pens with ad libitum access to one of the four diets: 75% steam-rolled barley + 10% barley silage with 10% FS or SS (non-DDG diets, NDG) and 46.5% barley + 10% barley silage + 30% DDG, with 8.5% FS or SS, all on a dry matter basis. Growth performance, ultrasound subcutaneous fat thickness, rib eye area (REA), and plasma FA were measured prior to and during the finishing period. At slaughter, samples of subcutaneous fat, perirenal fat, and Longissimus thoracis (LT) muscle were collected for FA analysis and carcass and meat quality were measured. Compared with CT cattle, TT tended to have less (P = 0.06) C18:2-c9,t11 (rumenic acid) in plasma and subcutaneous fat and a greater proportion (P < 0.05) of C18:0 in subcutaneous, perirenal, and LT fat. Cattle with TT genotype also tended (P < 0.1) to have more total saturated and less unsaturated (USFA) and monounsaturated fats (MUFA) and had less (P = 0.04) linoleic acid in LT. Ultrasound fat thickness, REA, and average diameter of adipocytes in subcutaneous fat at 12 wk were not affected (P > 0.39) by genotype. Generally, carcass and meat quality were similar (P > 0.1) among diets, although adding FS tended to increase (P = 0.06) total USFA of subcutaneous fat including omega-3 FA (P < 0.001). For the high-fat diets evaluated, CT cattle would have more potential to produce beef with enhanced health benefits than would TT cattle.

Leptin Gene Polymorphism in Goats Fed with Diet at Different Energy Level: Effects on Feed Intake, Milk Traits, Milk Fatty Acids Composition, and Metabolic State.

Simple SummaryIn this study it has been highlighted the role of a leptin polymorphism on goat milk yield and quality and of its interaction with the energy content of the diet. Energy did not interfere with genotype effect. The studied leptin polymorphism increased healthy fatty acids in milk, thus representing a potential tool to improve functional characteristics of goat milk.The study investigated the effects of a polymorphism at the LEP gene intron 1 microsatellite region and its interaction with diet energy level on feed intake, milk traits, milk fatty acid composition, and metabolic state in goats. Sixteen Girgentana lactating goats at mid-lactation, selected on the basis of their genotype (8 goats homozygous 266 bp/266 bp, L genotype; 8 goats heterozygous 266 bp/264 bp, H genotype), were fed ad libitum according to a change-over design, with two diets at different energy levels reached with different hay inclusion: low energy diet (LE)—100% of hay; and high energy diet (HE)—65% of hay. No differences in milk yield and composition or in dry matter intake were found between leptin genotypes or between diets. Leptin genotype had no effect on plasma metabolite concentrations. The differences between diets were recorded for plasma β-hydroxybutyric acid (BHBA) concentrations with higher (p = 0.01) values for the HE compared to the LE diet (0.44 vs. 0.24 mmol/L, respectively). Nonesterified fatty acid (NEFA) values seem to indicate a positive energy balance in goats. No interaction genotype per diet was evident for most of the studied parameters. Fatty acid composition was strongly influenced by LEP genotype: L goats, compared to H goats, showed higher levels of monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA), and 14:1/14:0 desaturation index; lower levels of saturated fatty acids (SFA); and a more favorable atherogenic index. These results seem to suggest an improvement of health characteristics of milk with the L genotype.

Leptin and Leptin Receptor Genes Are Associated With Obesity-Related Traits Changes in Response to Aerobic Training Program.

Leońska-Duniec, A, Jastrzębski, Z, Jażdżewska, A, Krzysztof, F, and Cięszczyk, P. Leptin and leptin receptor genes are associated with obesity-related traits changes in response to aerobic training program. J Strength Cond Res 32(4): 1036-1044, 2018-Leptin (LEP) and leptin receptor (LEPR) genes have been studied for their potential association with development of human obesity and its related complications. Therefore, we have decided to check whether selected body mass, body composition, and metabolic variables observed in physically active participants will be modulated by the polymorphisms. The genotype distribution was examined in a group of 201 women measured for chosen traits before and after the completion of a 12-week aerobic training program. Our results revealed a significant interaction between training and LEP genotype for glucose level. A training-related decrease in plasma glucose concentration in the LEP AG heterozygotes differed significantly from the change in the homozygotes. The polymorphism was also associated with fat-free mass (FFM), total body water (TBW), total cholesterol, triglycerides, and low-density lipoprotein cholesterol (LDL-C) levels. Another finding was a significant interaction between training and LEPR for LDL-C level. As opposed to AG and GG, AA homozygotes demonstrated a training-related decrease in LDL-C level. Our findings also showed that the LEPR G allele is connected with obesity-related traits. The participants with the GG genotype had higher body mass, body mass index (BMI), FFM, and TBW during the entire study period. This study provides evidence that polymorphisms in the LEP and LEPR genes are associated with the magnitude of the effects of regular physical activity on glucose and LDL-C levels, respectively. In addition, we found the association of the G allele of the LEPR polymorphism with body mass and BMI.

Генетические ресурсы быков-производителей по ДНК-маркерам в Республике Татарстан

Thanks to DNA diagnostics method it has become possible to identify the genotypes of marker genes of servicing bulls, that makes effective use of manufacturers with the desired gene alleles of economically useful features and is now the main task of breeding in cattle. The analysis and synthesis of polymorphism according to DNA markers of productivity: the kappa-casein (CSN3), diacylglycerol O-acyltransferase (DGAT1), beta-lactoglobulin (LGB), prolactin (PRL), growth hormone (GH), thyroglobulin (TG5), leptin ( LEP) in bulls of Tatarstan type of Kholmogorsk breeding, black-and-white and Kholstein breeding, belonging to tribal enterprises of Tatarstan: JSC Parent enterprise “Elita”, JSC “Menzelinsky breeding enterprise”, JSC “Bugulminsk breeding enterprise”. It was found that the bulls of Tatarstan type of Kholmogorsk breeds have the highest frequency of heterozygous genotypes for most genes, so according to CSN3 genotype AB - 34.2%, according to PRL genotype AB - 30.4%, to TG5 genotype TC - 35.9%, to LEP genotype TC - 66.7% and homozygous genotypes for the genes DGAT1, LGB, PRL, GH, LEP, respectively, AA genotype (47.2%), BB (48.7%), BB (2.2%), VV (20,0%), SS (33.3%). Genetic equilibrium is disrupted on gene of diacylglycerol acyltransferase in bulls of Tatarstan type of Kholmogory breed (χ2 = 4,72; P &lt;0.05) and a black-and-white breed (χ2 = 3,91; P &lt;0.05), and according to the somatropin gene only Kholmogory breed producers (χ2 = 5,42; P &lt;0.05).

Assessment of leptin gene (Arg223Gln) genotypes polymorphism in patients with coronary heart disease and obesity

Aim of study – to estimate leptin gene (Arg223Gln) genotypes polymorphism in patients with coronary heart disease and obesity. Materials and Methods. 222 patients with the coronary heart disease (CHD) and obesity have been comprehensively examined. All patients were on treatment in cardiologic unit of KUZ of the Kharkiv city hospital № 27, which is the basic clinic of Department of Internal Medicine № 2 and Clinical Immunology and Allergology of the Kharkiv National Medical University of MH of Ukraine. The comparison group consisted of 115 ischemic heart disease patients with normal body weight. 35 practically healthy persons formed the control group. Groups were comparable in age and sex. The study didn't include the patients with the serious accompanying pathology of respiratory organs, digestion, kidneys and persons with oncological diseases. Results. In the control group there was the following distribution of leptin gene (Arg223Gln) alleles and genotypes polymorphism frequency: 15 people were allele A that made 42.86 %, allele G – 20 people (57.14 %); genotypes G/G, A/A and G/G had 15 (42.86 %), 7 (20 %) and 13 (37.14 %) persons respectively. 42 patients with CHD were allele A, which made 36.52 %, allele G – 73 patients (63.48 %). Genotypes G/G, A/A and G/G had 47 (40.87 %), 20 (17.39 %) and 48 (41.74%) patients with CHD respectively. In group of patients with combination of CHD and obesity 71 patients (31.98 %) were allele A, allele G – 151 people (68.02 %); genotypes G/G, A/A and G/G – 81 (36.49 %), 33 (14.87 %) and 108 (48.64 %) respectively. Comparison of leptin gene (Arg223Gln) alleles and genotypes polymorphism frequency of detection between groups showed the reliable differences of alleles A, G and a genotype G/G. In patients with CHD and obesity allele G was 10.88 % more and genotype G/G was 11.5 % more, than in the control group. Allele A was 10.88 % more in the control group, than in patients with CHD and obesity (p < 0.05). Reliable differences between group of CHD patients and the control group in distribution of detected alleles and genotypes frequency of leptin gene (Arg223Gln) polymorphism were not found (p < 0.05). Conclusions. By results of the study allele G and a genotype G/G of leptin gene (Arg223Gln) polymorphism in patients with CHD has been associated with obesity.

Prediction of lactation persistency in crossbred cattle using genotype profile of lactation curve traits

The objective of the present study was to identify the best fit lactation model in relation to bovine leptin gene and to assess lactation persistency based on lactation curve traits in crossbred Karan Fires cattle. Incomplete gamma (Wood) function and exponential (Wilmink) function tests were used to describe the characteristics of lactation curve in first lactation. Woods model showed a comparatively better fit. Different types of lactation curves depicted by these cattle using data spread over a period of 15 years (1994 to 2009) were grouped into desired and nondesired type of lactation curve. Subsequently, genotype profiling was done using PCR-RFLP. A single nucleotide polymorphism identified in exon-2 region of bovine leptin gene, was associated with desired type of lactation curve and animals having TT genotype showed better persistency of milk yield. The results validated in test population had shown positive relationship between leptin genotypes and lactation curve traits. The inference from work has a potential application in breeding program of the country, where it may give support to existing expected producingability (EPA) based selection methodology followed for selection of dairy animals, by adding leptin genotype as one additional selection criterion for early selection in crossbred dairy bulls and cattle.

Impacts of a leptin SNP on growth performance and carcass characters in finishing steers studied over time.

A total of 2,948 steers (mean initial BW = 568.9 ± 49.4 kg) were used to evaluate the effect of the LEP R25C SNP genotype on feed intake, growth performance, and carcass characteristics over time. Steers were grouped into 5 blocks, each consisting of 10 pens initially, and then at approximately 24 d prior to the assigned slaughter date, cattle in each pen were randomly selected either to remain in the pen they were in (group A) or to be assigned to a new pen (group B). Steers were allocated to 5 blocks and 6 harvest weeks (-3, -2, 0, 2, 3, and 4 wk) relative to the projected end point. Steers were weighed and ultrasound scanned at 60 and 1 d prior to harvest. Leptin genotype affected ( ≤ 0.011) 12th-rib fat and i.m. fat percentage (IMF) for each slaughter group at both 60 and 1 d prior to slaughter, although rib eye area (REA) was not affected ( = 0.773) by leptin genotype 60 d prior to slaughter in any group. Time affected ( < 0.001) live BW as well as 12th-rib fat, REA, and IMF measured 60 and 1 d prior to each slaughter time. Dry matter intake was also higher ( = 0.003) for cattle of the animals homozygous for the T allele (TT) genotype compared to those with the animals homozygous for the C allele (CC) genotype (9.59 vs. 9.29 ± 0.075 kg). The LEP R25C genotype affected key traits related to carcass fatness; specifically, compared to cattle of the CC genotype, cattle of the TT genotype had a higher ( = 0.016) calculated empty body fat (29.1 vs. 28.8 ± 0.133%) and higher ( = 0.020 calculated yield grade (2.62 vs. 2.52 ± 0.035). Additionally, like for live measures, TT cattle tended ( = 0.093) to have a higher 12th-rib fat (13.2 vs. 12.8 ± 0.26 mm). However, the LEP R25C genotype did not affect KPH ( = 0.854) or marbling score ( = 0.240), nor did it affect any USDA quality measure ( ≥ 0.350). The leptin genotype also affected ( = 0.048) HCW, which was highest for steers of the TT genotype (400.9 vs. 403.5 ± 3.41kg). Results indicate that the leptin R25C genotype and time impacted most traits associated with fatness.

Leptin and leptin-receptor polymorphisms in fertile and infertile men

ABSTRACTThe association of leptin (LEP) -2548G/A and/or leptin receptor (LEPR) Gln223Arg polymorphisms with male infertility and plasma FSH, LH, and testosterone (T) levels was examined. The genotypes and allele frequency distributions of LEP -2548G/A and LEPR Gln223Arg polymorphisms were investigated in 150 fertile and 150 infertile men by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Also, plasma levels of FSH, LH, and T were measured using commercial ELISA kits. Frequencies of AA, AG and GG genotypes of LEP-2548G/A polymorphism were statistically different in fertile and infertile men (p=0.012). The AG genotype showed a protective effect which could decrease risk of male infertility about 3 fold (p = 0.004). We did not observe any differences in frequencies of LEPR Gln223Arg alleles and genotypes between groups (p > 0.05). Sperm counts from infertile men with the AG and GG genotypes of the LEP polymorphism were significantly higher than AA genotype (p<0.05). Moreover, infertile men who carried the RR genotype of LEPR showed a statistically higher percentage of sperm with progressive motility than individuals with other genotypes (p = 0.004). There was no correlation between different combinations of LEP and LEPR genotypes and LH, FSH, and T levels (p > 0.05). Our study suggests that the LEP -2548G/A polymorphism may play a role in male fertility and the AG genotype may have a protective effect through increasing sperm counts. The distribution of genotypes of LEP -2548G/A polymorphism are different in fertile and infertile males and may be a useful tool in evaluation of male infertility.Abbreviations: LEP: leptin; LEPR: leptin receptor; T: testosterone; FSH: follicle-stimulating hormone; LH: luteinizing hormone

Association of DGAT1 and leptin with fertility traits in Holstein cows

The objective of this study was to investigate relationship between the K232A mutation in the DGAT1 gene and the C963T mutation in the Leptin gene with reproduction traits. The study was conducted on 286 pure breed Holstein cows. In DGAT1 we found a favorable effect of AA genotype on age at the first calving (p˂0.15) and on conception rate after first service in heifers (p˂0.15). In the Leptin a positive effect of CC genotype on interval from calving to 1. service was observed (p˂0.05). A tendency for positive effect of CC genotype on age at the first service (p˂0.16) was observed as well. In another examined fertility traits we found no association with DGAT1 and Leptin genotypes. Present study brings a new information about studied SNP and such results may be used to assist genetic selection in dairy cattle.

Maternal and neonatal leptin and leptin receptor polymorphisms associated with preterm birth

Leptin (LEP) and leptin receptor (LEPR) are suggested to play a role in female reproduction and especially in pregnancy Both LEP and LEPR are synthesized by the pregnant female and embryo. The link between genetic polymorphisms of LEP and LEPR and preterm birth (PTB) is unknown. We studied maternal and neonatal LEP and LEPR genetic polymorphisms and the association with PTB. Blood for DNA analysis was collected from Israeli mothers and from venous umbilical of their respected idiopathic preterm newborns (24–36weeks, n=102) and control term newborns (>37weeks, n=158). Genotypes of maternal and neonatal LEP (rs7799039) and LEPR (rs1137101) polymorphisms were analyzed by restriction fragment length polymorphism analysis. Genotype-phenotype association was assayed using SPSS program. We found a significant independent increased risk of PTB for women and neonates bearing the homozygous AA form of LEP genotype; where women carrying AA LEP genotype had 2.53 fold ([CI] 1.367–4.685, p=0.03) and 2.38 fold ([CI] 1.150–4.915, p=0.019) increased risk for PTB compared to AG and GG genotypes, respectively. Neonates carrying the LEP AA genotype had a significant 2.8 fold increased risk for PTB compared to the AG genotype (CI11.040–7.577, p=0.042). Maternal LEPR polymorphism was significantly associated with severe PTB; where women carrying the AA and AG genotypes had a significant 4.32 and 4.76 fold increased risk for severe PTB compared to women carrying the GG genotype (CI=1.090–17.112 and 1.332–17.027, respectively p=0.035). In conclusion: maternal and neonatal LEP and LEPR polymorphisms are significantly associated with increased risk for PTB.

Comparison of feeding behavior between black and red Angus feeder heifers

The objective of this study was to compare feeding behavior between red and black Angus heifers during a 161-d finishing period as a potential explanation for performance differences. Sixty-eight single-sourced purebred red (n = 35) and black (n = 33) Angus heifers, leptin genotype TT, and average starting weight 360 kg (±19 kg) were used. Heifers were randomly and equally allocated into one of two feedlot pens, equipped with five feed bunks that recorded feeding behavior. Individual time spent at the feed bunk, interval between feeding events, feed intake, and meal frequency were recorded daily, and eating rate was calculated. Heifers were fed a barley-based diet (&gt;75% concentrate). After 161 d, at the end of the feeding period, feedlot performance was calculated as average daily gain (ADG) and gain to feed conversion rate. Additionally, carcass data were obtained from the abattoir. Overall, black Angus heifers ate more, spent more time at the feed bunk, and had more meals compared with red Angus (P &lt; 0.001). Red Angus heifers had better gain to feed ratios (P &lt; 0.02) and significantly more red heifers were assigned to Canadian yield category 1 (≥59% lean meat) compared with black heifers (P = 0.02), whereas black heifers had higher back fat thickness throughout the study (P ≤ 0.04). All other performance parameters (ADG and carcass weight) were not different.

Performance and carcass characteristics when sorting feedlot cattle on the basis of phenotype, and leptin genotype along with differential use of β-adrenergic agonists

Kononoff, P. J., Defoor, P. J., Engler, M. J., Swingle, R. S., James, S. Y., Deobald, H. M., Deobald, R. L., Woronuk, G. N. and Marquess, F. L. S. 2015. Performance and carcass characteristics when sorting feedlot cattle on the basis of phenotype, and leptin genotype along with differential use of β-adrenergic agonists. Can. J. Anim. Sci. 95: 455–463. Crossbred steers were used in a randomized complete block design to evaluate a feedlot cattle sorting system. The sorting system combined information on live body weight, ultrasound fat thickness, coat color, and genotype on the leptin R25C genotype. Using described sorting criteria, a total of four groups (Groups 1–4) of cattle were created along with a randomly selected unsorted control (Group 5), with Groups 1 through 5 representing experimental treatments, and placed in one of five pens within each block. Block was replicated 10 times thus n equaled 50. All cattle were administered zilpaterol hydrochloride except Group 3, which we hypothesized would have a greater proportion of cattle reaching a higher value Quality Grade, and as a result administered ractopamine hydrochloride. The initial body weight of cattle was similar (P=0.426) between the control Group and Groups 1–4. Initial fat, as measured by ultrasound, was also observed to be similar (P=0.256) between these two groups. Overall, when cattle included in Groups 1–4 were compared with Group 5, hot carcass weight was greater (P=0.040), while the proportion of excessively heavy weight carcasses was less (P=0.049). Additionally, hot carcass weight gain tended (P=0.096) to be higher for Groups 1–4 compared with Group 5. No differences (P≥0.129) were observed for calculated yield grade. On average, cattle included in the Sorting Groups 1–4 returned $23 more per head than those in Group 5.

Análisis de PCR-RFLP del gen de leptina y su asociación con características de la leche en ganado nativo (Bos indicus) de Irán

Se utilizó una muestra ganadera experimental para la caracterización de los genes y las frecuencias genotípicas y evaluar la asociación entre los polimorfismos de longitud del fragmento de restricción BsaAI en el gen de leptina y las características lácteas. Se recolectaron muestras de sangre de 390 vacas proporcionadas por el censo ganadero de la provincia de Guilán en Irán. La extracción de ADN genómico se basó en el método modificado de precipitación salina. El fragmento de 522 bp que comprende la región parcial del exón 3 e intrón 2 del locus del gen de leptina se amplificó mediante PCR-RFLP e iniciadores específicos. La digestión del fragmento amplificado con la enzima de restricción BsaAI reveló dos alelos de A y B con frecuencias de 0.447 y 0.553, y tres genotipos de AA, AB, BB con frecuencias de 0.185, 0.526 y 0.289 en la población estudiada, espectivamente. El resultado del contenido de polimorfismo fue 0.372 y para heterocigosis 0.526. Los resultados demostraron que la población estudiada estaba en equilibrio Hardy-Weinberg. El análisis estadístico indicó que el polimorfismo LEP-BsaAI tiene un efecto significativo en la producción de leche, porcentaje de grasa y proteína de la leche (P&lt;0.01). Animales portadores del genotipo heterocigoto (AB) produjeron 1.17 y 0.7 kg/d más leche que los animales homocigotos AA y BB, respectivamente. Los animales con el genotipo AA tuvieron mayor grasa (0.28 %) y porcentaje de proteína (0.17 %) que el genotipo AB. Tales resultados pueden utilizarse como criterios para facilitar la selección genética en losprogramas de cría animal.

THE INFLUENCE OF SINGLE NUCLEOTIDE POLYMORPHISM IN THE LEPTIN GENE ON SERUM ENERGY METABOLISM PARAMETERS IN CATTLE

The aim of this study was to test hypothesis that genotype TT in Czech Pied bulls, associated with higher leptinemia, will have significant effect on energy metabolism parameters in blood serum. The experiment was performed on the Czech Pied bulls in average age of 253 ± 13 days. The animals were sorted out into three groups according to the leptin genotype. The genotype TT was represented 20 animals, CT was represented 143 animals and CC was represented 127 animals. In the blood serum β-hydroxybutyrate (BHB) and non-esterified fatty acid (NEFA) were analyzed. One-way ANOVA revealed significant relation between serum concentration of NEFA and SNP genotype in leptin gene of Czech Pied bulls, but we failed to verify the hypothesis that genotype TT could affect some of monitored parameters.