An investigation into growth-related genes in the Australasian snapper, Chrysophrys auratus

<p>Growth is a complex quantitative trait that is controlled by a variety of genetic and environmental factors. Due to its significance in animal breeding programmes, growth is a commonly studied trait in agriculture and aquaculture species. The Australasian snapper, Chrysophrys auratus, supports significant commercial and recreational fisheries in New Zealand and has the potential to be developed as a new aquaculture species. However, the relatively slow growth rate of C. auratus is a constraint and little is known of the specific regulation of growth in this species. The overall aim of this thesis research was to use genome sequence data and transcriptomics to investigate the loci that influence growth rate of C. auratus. In Chapter Two, the C. auratus Growth Hormone (GH) gene was identified in the reference genome and the structure and polymorphisms were characterised using re-sequenced data. The GH gene was approximately 5,577 bp in length and was comprised of six exons and five introns. Large polymorphic repeat regions were found in the first and third introns, and putative transcription factor binding sites were identified. Phylogenetic analysis of the GH genes of Perciform fish showed conserved non-coding regions and highly variable non-coding regions. The amino acid sequences and putative secondary structures were also largely conserved across this order. In Chapter Three, the genetic variation of two large intronic repeat regions were assessed in wild C. auratus populations and shown to be polymorphic. The intron 1 locus was then assessed in slow- and fast-growing C. auratus for associations with growth rate. No significant differences were detected in the variation between groups; however, trends seen in the results corroborated other studies of an association between shorter introns and increased gene expression. Further investigation with a larger sample size is needed. A high level of heterozygosity was detected in all populations used in this study and may be due to negative selection acting on one allele (485). In Chapter Four, gene expression data was compared between C. auratus at high (21 °C) and low (13 °C) temperatures to investigate how the gene regulation of growth is influenced by temperature. The high temperature treatment (HTT) was characterized by a large number of differentially expressed genes associated with biosynthesis, skeletal muscle components, and catalytic activity while the low temperature treatment (LTT) had an upregulation of genes associated with important degradation pathways. The results of this study also suggest the action of negative feedback on growth regulation in the HTT, which may be a result of chronic heat stress. This thesis research represents one of the first studies to explore the genetic regulation of growth in C. auratus and makes a significant contribution to the field of research into growth, not only in C. auratus, but also other fish species. The findings presented in this thesis may be applied to a selective breeding programme of C. auratus that aimed to increase the growth rate, and consequently, improve its economic viability as a commercial aquaculture species in New Zealand.</p>

An investigation into growth-related genes in the Australasian snapper, Chrysophrys auratus

<p>Growth is a complex quantitative trait that is controlled by a variety of genetic and environmental factors. Due to its significance in animal breeding programmes, growth is a commonly studied trait in agriculture and aquaculture species. The Australasian snapper, Chrysophrys auratus, supports significant commercial and recreational fisheries in New Zealand and has the potential to be developed as a new aquaculture species. However, the relatively slow growth rate of C. auratus is a constraint and little is known of the specific regulation of growth in this species. The overall aim of this thesis research was to use genome sequence data and transcriptomics to investigate the loci that influence growth rate of C. auratus. In Chapter Two, the C. auratus Growth Hormone (GH) gene was identified in the reference genome and the structure and polymorphisms were characterised using re-sequenced data. The GH gene was approximately 5,577 bp in length and was comprised of six exons and five introns. Large polymorphic repeat regions were found in the first and third introns, and putative transcription factor binding sites were identified. Phylogenetic analysis of the GH genes of Perciform fish showed conserved non-coding regions and highly variable non-coding regions. The amino acid sequences and putative secondary structures were also largely conserved across this order. In Chapter Three, the genetic variation of two large intronic repeat regions were assessed in wild C. auratus populations and shown to be polymorphic. The intron 1 locus was then assessed in slow- and fast-growing C. auratus for associations with growth rate. No significant differences were detected in the variation between groups; however, trends seen in the results corroborated other studies of an association between shorter introns and increased gene expression. Further investigation with a larger sample size is needed. A high level of heterozygosity was detected in all populations used in this study and may be due to negative selection acting on one allele (485). In Chapter Four, gene expression data was compared between C. auratus at high (21 °C) and low (13 °C) temperatures to investigate how the gene regulation of growth is influenced by temperature. The high temperature treatment (HTT) was characterized by a large number of differentially expressed genes associated with biosynthesis, skeletal muscle components, and catalytic activity while the low temperature treatment (LTT) had an upregulation of genes associated with important degradation pathways. The results of this study also suggest the action of negative feedback on growth regulation in the HTT, which may be a result of chronic heat stress. This thesis research represents one of the first studies to explore the genetic regulation of growth in C. auratus and makes a significant contribution to the field of research into growth, not only in C. auratus, but also other fish species. The findings presented in this thesis may be applied to a selective breeding programme of C. auratus that aimed to increase the growth rate, and consequently, improve its economic viability as a commercial aquaculture species in New Zealand.</p>

Growth Hormone Gene Polymorphism and its Relation to Quail Growth and Carcass

In this study, it was aimed to determine the polymorphism of GH (growth hormone) gene in Japanese quails and the relationships between these genes and body weight and carcass traits. 3 genotypes (AA, AB and BB), 2 (A and B) alleles were detected by cutting the GH intron 1 region with restriction enzyme MspI. As a result of variance analysis, it was determined that the hatching weights of the animals with B allele and liver weights were higher. Thus, it is seen that GH gene and PCR-RFLP technique can be used in breeding studies.

MILK PRODUCTIVITY OF BLACK-AND-WHITE CATTLE WITH DIFFERENT GENOTYPES OF PROLACTIN AND SOMATOTROPIN

Изучена взаимосвязь аллельных вариантов генов пролактина и соматотропина с показателями молочной продуктивности коров черно-пестрой породы по 1 и 3 лактации. У первотелок, как и у полновозрастных животных, наиболее высокий удой (4642 и 6240 кг), количество молочного жира (174,1 и 215,0 кг) и молочного белка (149,0 и 182,5 кг) достигнуты в группе с генотипом PRL АА. По массовой доле жира и белка в молоке коровы с генотипом PRL ВВ достоверно превосходили животных с генотипом PRL АА на 0,12% (Р<0,05) и 0,05% (Р<0,05) соответственно. По гену соматотропина наибольший уровень молочной продуктивности выявлен у коров с генотипом GH LL при достоверном преимуществе над GH VV у первотелок по удою на 439 кг (Р<0,01), выходу молочного жира — на 13,6 кг (Р<0,001), выходу молочного белка — на 15,3 кг (Р<0,01). У полновозрастных коров превышение над остальными группами было только по удою — на 219—548 кг (Р<0,05). Наибольшая жирномолочность характерна животным с генотипом GH VV по 1 лактации — 3,83% и по 3 лактации — 3,82%, а лучшая белковомолочность — коровам, имеющим аллель V гена GH: 3,21 и 3,23% соответственно. Полученные данные свидетельствуют о более высоком уровне молочной продуктивности у коров с генотипом PRL АА и GH LL, но лучшая жирномолочность и белковомолочность отмечены у особей, имеющих в своем генотипе аллели В гена PRL и V гена GH. The interrelation of allelic variants of prolactin and somatotropin genes with indicators of milk productivity of black-and-white cows for the 1st and 3rd lactation was studied. The highest milk yield (4642 and 6240 kg) amount of milk fat (174.1 and 215.0 kg) and milk protein (149.0 and 182.5 kg) were in the group with the PRL AA genotype in first-calf heifers as well as in full-age animals. In terms of the mass fraction of fat and protein of milk, the cows with the PRL BB genotype significantly exceeded animals with the PRL AA genotype by 0.12% (P<0.05) and 0.05% (P<0.05), respectively. According to the somatotropin gene, the highest level of milk productivity was revealed in cows with the GH LL genotype with a significant advantage over GH VV in first-calf heifers in milk yield by 439 kg (P<0.01), milk fat yield by 13.6 kg (P<0.001), milk protein yield by 15.3 kg (P<0.01). The excess over the other groups in full-age cows was only in terms of milk yield that was by 219-548 kg (P<0.05). The highest protein content of milk is a characteristic of animals with the GH VV genotype, 3.83% is for the 1st lactation and 3.82% is for the 3rd lactation, and the best protein content of milk in cows with V allele of the GH gene is 3.21 and 3.23%, respectively. The obtained data indicated a higher level of milk productivity in cows with the PRL AA and GH LL genotypes but the best fat and milk content was noted in cows with alleles B of the PRL gene and V of the GH gene in their genotype.

DAIRY PRODUCTIVITY OF FIRST COWS WITH DIFFERENT GENOTYPES BY GROWTH GENE

The aim of the study was to study the allelic polymorphism of the growth hormone gene in a group of cows of the Montbeliard breed and to search for associations of its different genotypes with the parameters of the dynamics of milk yield during lactation. The research was conducted in the Department of Animal Genetics and Biotechnology of the Institute of Animal Breeding and Genetics of NAAS on a group of 30 cows of the Montbeliard cattle breed from PSP "Zhadkivske" of Chernihiv region. Genomic DNA was isolated from blood leukocytes by standard methods using the set "DNA-sorb-B" ("Ampli-Sense", Russia). Dairy productivity of first-born cows was determined monthly by control milkings. Types of lactation curves were studied according to the method of A. S. Emelyanov (1953). Polymorphism of the growth hormone (GH) gene in our first-born cows is represented by two alleles L I V, the frequency of which differs, and the frequencies of genotypes differ accordingly. In the studied group of animals, all possible genotypes of the growth hormone gene were identified: 25 animals (83%) have the GHLL genotype, 4 (13%) have the GHLV genotype, and only one cow has the GHVV genotype. The frequency of the L allele is 0.9, and the V allele is 0.1. The mean expectation for 305 days of the first lactation of a group of cows with the GHLL genotype was 352 kg higher than the expectations in the group of heterozygous cows with the GHLV genotype. In terms of milk fat and protein yield, cows with GHLL genotype were significantly dominated by cows with GHLV genotypes (74 kg fat and 36 kg protein, respectively, p < 0.001). Analysis of the dynamics of monthly milk yield of the studied cows for 305 days of the first lactation showed that the productivity of cows with GHLL genotype exceeds the average monthly milk yield of other groups of animals at the beginning (from 1 to 3 months), at the peak of lactation (4th month) and at the end of lactation (from 8 to 10 months). In general, during the 305 days of the first lactation, first-borns with the GHLL genotype had better milk yields compared to their peers with other growth hormone gene genotypes. Analysis of variance showed that the obtained share of variability in milking in animals with different genotypes of the GH gene is due to random factors. Analysis of lactation curves of primiparous women showed that milk yield of cows with all variants of genotypes in the GH gene gradually increased and reached its peak at 3–4 months of lactation, and then gradually decreased. This lactation curve, according to the classification of A. S. Emelyanov is characteristic of animals with high and stable lactation, and cows are able to digest food well and produce high hopes. \ Thus, a statistically significant difference in quantitative and qualitative characteristics of milk productivity of cows of Montbeliard breed with different variants of genotypes by GH gene on the example of a group of cows from "Zhadkivske" Chernihiv region suggests that the use of genetic markers, in particular the growth hormone GH selection of selection and further formation of the herd in the direction of increasing milk productivity.

Appropriate growth models to describe early growth of Kejobong goat based on Growth Hormone (GH) gene sequence analysis

The objectives of this study were to reveal appropriate growth models describing early growth of Kejobong goat based on Growth Hormone (GH) gene sequence analysis. A total of 35 DNA samples and 1.960 records of quantitative traits of Kejobong goat were collected. The exon 3 of GH gene was amplified and was sequenced to determine the SNP. Body weight and body measurements of the goats were taken at 0-14 weeks of age. Four non-linear growth models were applied for analysis of growth to compare growth performance of different genotypes by Non-Linear Mixed Model. A non-synonymous mutation (g1170AG) genotyped into GG, AG and AA was significantly associated with growth traits. Animals with heterozygous genotype AG showed higher growth traits than animals with homozygous genotype AA. Nonetheless, animals with homozygous genotype GG had the same growth traits with those animals with heterozygous genotype AG and homozygous genotype AA. The most fitted model for describing body weight was Von Bertalanffy model, while for describing wither height and hip height was Brody model. SNP at exon 3 of the GH gene can be used as genetic marker for improvement of growth traits of Kejobong goats.

Polymorphism Exploration of Growth Family (GH, GHRH and PIT-1) Genes Polymorphisms of Local Swamp Buffalo for Productivity Improvement in North Tapanuli Regency, North Sumatra

Genetic improvement of livestock productivity can be done through molecular selection on the genes controlling growth traits. Genetic polymorphism of the growth family (GH, GHRH, and PIT1) genes were studied in local swamp buffalo (106 hds.) from a government buffalo breeding station (46 heads) and smallholders (60 heads) in North Tapanuli District, North Sumatra Province. Genotype variants of the three genes were identified by PCR-RFLP method using restriction enzymes of MspI (GH gene), HaeIII (GHRH gene) and HinfI (PIT -1 gene). Genotyping on individual GH_g.1547T>C, GHRH_g.4666G>C, and PIT -1_g.1256G >A loci resulted only one type genotype, respectively TT, CC, an d AA, with one type of allele, respectively T, C, and A. Heterozygosity observation (Ho) and expectation (He) values values and the PIC value for each locus was 0.00. It could be suggested to increase genotype frequenciest of the three growth genes that are positively associated with the growth traits and economic traits of the buffalo.