Analysis on DNA sequence of KiSS-1 gene and its association with litter size in goats

Regulatory Effects of the Kiss1 Gene in the Testis on Puberty and Reproduction in Hezuo and Landrance Boars

Kisspeptin, a neuropeptide encoded by the Kiss1 gene, combines with its receptor Kiss1R to regulate the onset of puberty and male fertility by the hypothalamic-pituitary-gonadal axis. However, little is known regarding the expression signatures and molecular functions of Kiss1 in the testis. H&E staining revealed that well-arranged spermatogonia, spermatocytes, round and elongated spermatids, and spermatozoa, were observed in 4-, 6-, and 8-month-old testes compared to 1- and 3-month-old testes of Hezuo pigs; however, these were not observed in Landrance until 6 months. The diameter, perimeter, and cross-sectional area of seminiferous tubules and the perimeter and area of the tubular lumen increased gradually with age in both pigs. Still, Hezuo pigs grew faster than Landrance. The cloning results suggested that the Hezuo pigs' Kiss1 CDS region is 417 bp in length, encodes 138 amino acids, and is highly conserved in the kisspeptin-10 region. qRT-PCR and Western blot indicated that the expression trends of Kiss1 mRNA and protein were essentially identical, with higher expression levels at post-pubertal stages. Immunohistochemistry demonstrated that the Kiss1 protein was mainly located in Leydig cells and post-pubertal spermatogenic cells, ranging from round spermatids to spermatozoa. These studies suggest that Kiss1 is an essential regulator in the onset of puberty and spermatogenesis of boars.

Association of the KiSS1 gene with litter size in Cyprus and Iraqi black goats

Aim:

The study investigated the genetic polymorphism of the kisspeptin (KiSS1) gene and its relationship with litter size in Cyprus and Iraqi black goats.

Materials and Methods:

Blood samples (n=124) were collected from the two goat breeds reared at the Agricultural Research-Ruminant Research Station Breeding Station, Baghdad, Iraq. Genomic DNA was isolated using a DNA extraction kit. Polymerase chain reaction (PCR) was used to amplify the KiSS1 gene. All PCR products were sequenced and samples were used for further analysis using NCBI-Blast online on the exon 1 (595 bp) region of the KiSS1 gene.

Results:

The results of this study revealed a significantly (P<0.05) larger litter size of the Cyprus goat breed than in the Iraqi black goats in the first and second parity. Three (893G/C, 973C/A, and 979T/G) substitutions relative to the KiSS1 gene reference sequence (GenBank ID: J × 047312.1, KC989928.1) were identified. Only the mutation g893G>C was identified as a single nucleotide polymorphism (SNP) associated with litter size. Furthermore, the average alleles in KiSS1 gene of both types of goats 0.567 and 0.3715 GG, were recorded. The genotyping at locus g893C>G was demonstrating domination of fecundity quality litter size, Both genotypes SNP of GC were classified at this marked region of KiSS1 gene.

Conclusion:

The study concluded that the role of the KiSS1 gene in fecundity, revealing the status of this gene as an indicator in the assisted of caprine breeding selection.

The kisspeptin system in domestic animals: what we know and what we still need to understand of its role in reproduction

The discovery of the kisspeptin (Kp) system stirred a burst of research in the field of reproductive neuroendocrinology. In the last 15 yr, the organization and activity of the system, including its neuroanatomical structure, its major physiological functions, and its main pharmacological properties, were outlined. To this endeavor, the use of genetic tools to delete and to restore Kp system functionality in a specific tissue was essential. At present, there is no question as to the key role of the Kp system in mammalian reproduction. However, easily applicable genetic manipulations are unavailable for domestic animals. Hence, many essential details on the physiological mechanisms underlying its action on domestic animals require further investigation. The potentially different effects of the various Kp isoforms, the precise anatomical localization of the Kp receptor, and the respective role played by the 2 main populations of Kp cells in different species are only few of the questions that remain unanswered and that will be illustrated in this review. Furthermore, the application of synthetic pharmacologic tools to manipulate the Kp system is still in its infancy but has produced some interesting results, suggesting the possibility of developing new methods to manage reproduction in domestic animals. In spite of a decade and a half of intense research effort, much work is still required to achieve a comprehensive understanding of the influence of the Kp system on reproduction. Furthermore, Kp system ramifications in other physiological functions are emerging and open new research perspectives.

Genome-wide association analysis reveals the genetic locus for high reproduction trait in Chinese Arbas Cashmere goat

BACKGROUND

Litter size is the most important reproductive trait which plays a crucial role in goat production. Therefore, improvement of litter size trait has been of increasing interest in goat industry as small improvement in litter size may lead to large profit. The recent Cashmere goat breeding program produced a high-reproductive genetic line of Arbas Cashmere goat. But the genetic mechanism of high reproduction rate remains largely unknown in this Chinese native goat breed. To address this question, we performed a genome-wide association studies (GWAS) using two groups of goats varying in fecundity.

OBJECTIVES

Our study was aimed to investigate the significant SNPs and genes associated with high reproduction trait in Inner Mongolia Arbas Cashmere Goat.

METHODS

We used logistic model association to perform GWAS using 47 goats from high fecundity group (~ 190%) and 314 goats from low fecundity group (~ 130%) of the Arbas Cashmere goat breed.

RESULTS

We identified 66 genomic regions associated with genome wide significant level wherein six loci were found to be associated with reproduction traits. Further analysis showed that five key candidate genes including KISS1, KHDRBS2, WNT10B, SETDB2 and PPP3CA genes are involved in goat fecundity trait. Gene ontology enrichment analysis revealed that several biological pathways could be involved in the variation of fecundity in female goats.

CONCLUSIONS

The identified significant SNPs or genes provide useful information about the underlying genetic control of fecundity trait which will be helpful to use them in goat breeding programs for improving the reproductive efficiency of goats.

Association of kisspeptin gene (KISS1) with litter size in migratory Gaddi goats in western Himalayan state of Himachal Pradesh

Migratory goat farming, practiced by nomadic communities is common in Himalayan regions. Gaddi also known as ‘White Himalayan goat’ is the predominant goat breed constituting 60–65% of total goats in the state. The Kisspeptin gene (KISS1) that encodes kisspeptin protein is considered to be a candidate gene affecting multiple birth in goats. The present study was carried out to identify polymorphism at kisspeptin (KISS1 gene) and its association with litter size in migratory Gaddi goat. Polymorphism of KISS1 gene was investigated in Gaddi goats (89) using PCR-RFLP and DNA sequencing approach. PCR-RFLP analysis at KISS1 locus revealed 3 different genotypes, viz. AA with undigested one fragment at 377 bp, TT with two digested fragments at 256 and 121 bp, and AT with three fragments at 377, 256 and 121 bp. The frequencies of AA, AT and TT genotypes were 0.17, 0.52 and 0.31, respectively while the frequency of A and T alleles was 0.43 and 0.57. AT genotype was predominant genotype while AA genotype was having least frequency among the goats screened. The observed allele number (No) and effective allele number (Ne) were 2 and 1.96, respectively. Observed heterozygosity (Hobs), expected heterozygosity (Hexp) and PIC values estimated were 0.52, 0.49 and 0.37, respectively. Hobs and PIC values indicated that sufficient genetic variation exist at the locus. Sequencing of representative sample of different genotypes confirmed presence of SNP (T125A) as detected by PCR-RFLP. The mean litter size for animals belonging to AA, AT and TT genotypes were 1.12±0.08, 1.34±0.11 and 1.73±0.15 kids, respectively. Significant association of genotypes was observed with litter size in Gaddi goat. The study detected association between allele T in KISS1 gene and litter size. Study on additional data based on more number of animals in diversified flocks should be carried out for validation of the preliminary findings.

Identification of mutations in BMP15 and GDF9 genes associated with prolificacy of Markhoz goats

The Markhoz is a local goat breed in the Kurdistan region of Iran. The mohair obtained from these animals plays an important cultural role and is used for making local clothes in the Kurdistan region. This breed is a low-fecundity local goat, and searching for genes associated with fertility of these goats is important for their breeding. Moreover, this research is complementary to prior studies of candidate genes associated with fertility. The growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15) are attractive candidates expressed by the oocyte and are associated with increased ovulation rate in sheep. However, there are no reports on single nucleotide polymorphisms associated with fertility of Markhoz goats. Hence, we studied these candidate genes and found two novel mutations (g.233C>A and g.755T>G) in GDF9 exon I and in BMP15 exon II, respectively. Furthermore, we investigated their association with prolificacy. These nucleotide changes are detectable with the PCR-RFLP method and can be used in the screening for highly fecund goats. Both of the mutations significantly increased litter size in heterozygote form for BMP15 and homozygote form for GDF9 in this goat breed. Homozygote females for the BMP15 mutation were not identified in the Markhoz breed, which is similar to the situation found in Belclare sheep, small-tailed Han sheep, and Jining Grey goats.

Association analysis of polymorphism in KiSS1 gene with reproductive traits in goats

Understanding the genetic information of related genes is helpful for the selection and breeding course through marker assisted selection. The aim of the current study was to detect polymorphisms of the KiSS1 gene in 137 animals, including Baladi, Zaraibi and Damascus goat breeds by PCR-RFLP, and DNA sequencing and to investigate the association between these variants and reproductive traits. Comparison of the nucleotide sequence indicated the substitution of T with A at position 121 (T121A) in the intron 1 of the KiSS1 gene in all goat breeds. This substitution distorts the restriction site of the XmnI restriction enzyme and consequently two genotypes were detected (TA and TT). The T121A SNP is associated significantly with litter size in Damascus and Zaribi breeds (p=0.025 and 0.001, respectively). The animals with the TT genotype in Damascus and Zaribi breeds had a significantly higher estradiol_17β level than that recorded in TA genotype at estrus phase (p=0.013 and 0.028, respectively) and late-luteal phase (p=0.067 and 0.041, respectively) of the estrus cycle. Furthermore, animals with the TT genotype in Damascus and Zaribi breeds had significant higher progesterone level at mid-luteal (p=0.037 and 0.045, respectively) phase. Meanwhile, there were no significant differences in progesterone level in late-luteal phase between both genotypes in Zaribi breed (p=0.267). The current trial indicated that the prolific TT genotype in both Damascus and Zaribi breeds had superior estradiol_17β level at estrus phase and an eminent progesterone level at both early and mid-luteal phases of the estrous cycle.

Influences of melatonin treatment, melatonin receptor 1A (MTNR1A) and kisspeptin (KiSS-1) gene polymorphisms on first conception in Sarda ewe lambs

In order to investigate if the melatonin receptor 1A (MTNR1A) and kisspeptin (KiSS-1) genes influence the reproductive response to melatonin treatment, 510 Sarda ewe lambs were divided into groups C (control) and M; Group M received one melatonin implant (18 mg). After 35 days rams were introduced for 40 days and subsequent lambing dates and number of newborns were recorded. The MTNR1A gene Exon II and KiSS-1 gene Exon I were amplified and genotyped by restriction fragment length polymorphism (RFLP) and single-strand conformation polymorphism analysis. Two single nucleotide polymorphisms (SNPs; C606T and G612A) in MTNR1A and one (G1035A) in KiSS-1 were found. The most frequent genotypes were G/G (63%) and C/C (53%) for MTNR1A and G/G (92%) for KiSS-1. Treated animals showed a higher lambing rate (P < 0.05) and an advanced lambing date (P < 0.05) compared with controls. The three SNPs did not influence the onset of reproductive activity. The majority of the G/G animals of Group M lambed before 190 days after ram introduction (P < 0.05), while in Group C a higher number of G/G animals lambed after this date. Data revealed the positive effect of melatonin treatment on the time of first conception in ewe lambs and highlighted that the G/G genotype of the MTNR1A gene is able to influence the reproductive response to melatonin treatment.

The Application of Genomic Technologies to Investigate the Inheritance of Economically Important Traits in Goats

Goat genomics has evolved at a low pace because of a lack of molecular tools and sufficient investment. Whilst thousands and hundreds of quantitative trait loci (QTL) have been identified in cattle and sheep, respectively, about nine genome scans have been performed in goats dealing with traits as conformation, growth, fiber quality, resistance to nematodes, and milk yield and composition. In contrast, a great effort has been devoted to the characterization of candidate genes and their association with milk, meat, and reproduction phenotypes. In this regard, causal mutations have been identified in the αS1-casein gene that has a strong effect on milk composition and the PIS locus that is linked to intersexuality and polledness. In recent times, the development of massive parallel sequencing technologies has allowed to build a reference genome for goats as well as to monitor the expression of mRNAs and microRNAs in a broad array of tissues and experimental conditions. Besides, the recent design of a 52K SNP chip is expected to have a broad impact in the analysis of the genetic architecture of traits of economic interest as well as in the study of the population structure of goats at a worldwide scale.

Association analysis between variants in KISS1 gene and litter size in goats

Background

Kisspeptins are the peptide products of KISS1 gene, which operate via the G - protein-coupled receptor GPR54. These peptides have emerged as essential upstream regulators of neurons secreting gonadotropin-releasing hormone (GnRH), the major hypothalamic node for the stimulatory control of the hypothalamic–pituitary– gonadal (HPG) axis. The present study detected the polymorphisms of caprine KISS1 gene in three goat breeds and investigated the associations between these genetic markers and litter size.

Results

Three goat breeds (n = 680) were used to detect single nucleotide polymorphisms (SNPs) in the coding regions with their intron–exon boundaries and the proximal flanking regions of KISS1 gene by DNA sequencing and PCR–RFLP. Eleven novel SNPs (g.384G>A, g.1147T>C, g.1417G>A, g.1428_1429delG, g.2124C>T, g.2270C>T, g.2489T>C, g.2510G>A, g.2540C>T, g.3864_3865delCA and g.3885_3886insACCCC) were identified. It was shown that Xinong Saanen and Guanzhong goat breeds were in Hardy-Weinberg disequilibrium at g.384G>A locus (P < 0.05). Both g.2510G>A and g.2540C>T loci were closely linked in Xinong Saanen (SN), Guanzhong (GZ) and Boer (BG) goat breeds (r² > 0.33). The g.384G>A, g.2489T>C, g.2510G>A and g.2540C>T SNPs were associated with litter size (P<0.05). Individuals with AATTAATT combinative genotype of SN breed (SC) and TTAATT combinative genotype of BG breed (BC) had higher litter size than those with other combinative genotypes in average parity. The results extend the spectrum of genetic variation of the caprine KISS1 gene, which might contribute to goat genetic resources and breeding.

Conclusions

This study explored the genetic polymorphism of KISS1 gene, and indicated that four SNPs may play an important role in litter size. Their genetic mechanism of reproduction in goat breeds should be further investigated. The female goats with SC1 (AATTAATT) and BC7 (TTAATT) had higher litter size than those with other combinative genotypes in average parity and could be used for the development of new breeds of prolific goats. Further research on a large number of animals is required to confirm the link with increased prolificacy in goats.

Expression of a tumor-associated gene, LASS2, in the human bladder carcinoma cell lines BIU-87, T24, EJ and EJ-M3

Homo sapiens longevity assurance homolog 2 of yeast LAG1 (LASS2), a metastasis suppressor gene of human cancer, is the most abundantly expressed member of the ceramide synthase gene family. Expression of LASS2 has been reported in carcinomas of the prostate, liver and breast. However, there has been no report on the expression of LASS2 in human bladder cancer cell lines. In order to investigate the expression and potential role of this new tumor metastasis supressor gene in human bladder cancer, we compared the proliferation, metastasis and invasion among the BIU-87, T24, EJ and EJ-M3 human bladder cancer cell lines. The mRNA expression levels of the LASS2 gene were examined using real-time quantitative PCR (qPCR). The expression levels of LASS1 and LASS3 mRNA were used as references. The protein expression level of the LASS2 gene was detected using western blotting. The most aggressive of these four human cancer cell lines was observed to be EJ-M3. The expression of LASS2 mRNA was significantly correlated with diverse proliferation, metastasis and invasion. The expression levels of LASS1 and LASS3 mRNA were not correlated with these parameters. At the protein level, we observed that the more aggressive the cancer cell line, the lower the LASS2 protein expression level. Therefore, LASS2 expression may be correlated with the development and progression of human bladder cancer and may be a prognostic indicator for this cancer.

Molecular characterization of growth differentiation factor 9 and its spatio-temporal expression pattern in gibel carp (Carassius auratus gibelio)

Growth differentiation factor 9 (GDF9) is a member of the transforming growth factor β (TGF-β) superfamily with a key role in regulating follicle development. In this study, the GDF9 full-length genomic DNA and cDNA were isolated and characterized from the gibel carp ovary using rapid-amplification of cDNA ends (RACE) and LD-PCR. The full-length genomic DNA and cDNA sequences of GDF9 are 3979 and 2044 bp which code 428 amino acid residues with a specific RKKR protease cleavage site of TGF-β superfamily. Sequence analysis showed that gibel carp was similar to zebrafish and other fish species. Spatio-temporal expression analysis using real-time quantitative PCR revealed that GDF9 mRNA was largely expressed in ovary and testis. GDF9 is mainly present at stage I follicles indicating its important role in early follicles development. The same result was obtained in immunohistochemistry localization of GDF9 protein. Within the follicle, the follicle layer cells were barely expressed whereas GDF9 mRNA was mostly expressed in the oocytes. Supplemented with human chorionic gonadotropin (hCG) in isolated follicles, the expression of GDF9 mRNA was increased firstly and then decreased. The results of this study indicated that GDF9 gene played a role in fish during development of follicles, especially in the early stage follicles.

Expression and prognostic significance of a new tumor metastasis suppressor gene LASS2 in human bladder carcinoma

The LASS2 gene has been identified as a new tumor metastasis suppressor gene and has been seen to correlate with the degree of invasion and recurrence in carcinomas of prostate, breast, liver, ovarian, and pancreas. However, expression and prognostic significance of LASS2 in human bladder carcinoma are largely unknown. In this study, the protein expression of LASS2 in 80 patients with different stages was detected by immunohistochemical staining. The prognostic value of LASS2 in bladder cancers can also be assessed by a long-term follow-up investigation. The mRNA expression level of the LASS2 gene was examined using real-time quantitative PCR (qPCR) in human bladder carcinoma and paired non-tumor bladder tissues, which were obtained from 30 patients who underwent total cystectomy. We found that patients with LASS2-negative bladder cancer were linked to poor clinical prognosis. The expression of LASS2 mRNA was significantly correlated with clinical stage (P < 0.001), depth of tumor invasion (P < 0.001), and recurrence (P < 0.001). Thus, LASS2 expression may be correlated with the development and progression of human bladder carcinoma and may be a prognostic indicator for this carcinoma.

Polymorphisms of KiSS-1 and GPR54 genes and their relationships with litter size in sheep

The KiSS-1 and GPR54 genes were studied as candidate genes for the prolificacy in sheep. Four pairs of primers were designed to detect single nucleotide polymorphisms of exon 1 of KiSS-1 gene and exon 1, exon 2 and partial exon 5 of GPR54 gene in high fecundity breeds (Small Tail Han and Hu sheep) and low fecundity breeds (Dorset, Texel and Corriedale sheep) by PCR-SSCP. Polymorphisms in exon 1 of KiSS-1 gene were detected in prolific Small Tail Han sheep (AA, AB and BB genotypes) and Hu sheep (AA and CC genotypes), no polymorphism was found in low fecundity sheep breeds (only AA genotype). Polymorphisms in exon 2 of GPR54 gene were detected in prolific Hu sheep (DD and EE genotypes) and no polymorphism was found in prolific Small Tail Han sheep and low fecundity sheep breeds (only DD genotype). No polymorphism was detected in exon 1 and partial exon 5 of GPR54 gene in five sheep breeds. The polymorphic genotypes were sequenced. While compared the BB genotype with the AA genotype, one nucleotide mutation (G1035A) was detected, which resulted in amino acid change, Val25Met. Five nucleotide mutations were detected from AA to CC genotype (C981T, C996T, T997C, C1034G, C1039T), and among them four caused amino acid changes, that is, Arg7Trp, Phe12Leu, Asn24Lys, Ala26Val. While compared the EE genotype with the DD genotype, two nucleotide mutations (T2360C, A2411C) were detected, which gave rise to amino acid changes, Met90Thr and Asp107Ala, respectively. Genotype frequencies of AA, BB and AB were 0.62, 0.05 and 0.33 in Small Tail Han sheep, respectively. The Small Tail Han sheep ewes with genotype BB or AB had 0.88 (P < 0.05) or 0.51 (P < 0.05) lambs more than those with genotype AA; the Small Tail Han sheep ewes with genotype BB had 0.37 (P > 0.05) lambs more than those with genotype AB. These results preliminarily indicated that the KiSS-1 gene may have some association with prolificacy in sheep.

SNPs discovery and CAPS marker conversion in soybean

To discover new SNPs and develop an easy assay method in soybean, we compared the high-throughput pyrosequencing ESTs with whole genome sequences in different soybean varieties and identified 3899 SNPs. Transitions were found to be much more frequent than transversions in these SNPs. We found that SNPs were widely distributed in the soybean genome, targeting numerous genes involved in various physiological and biochemical processes influencing important agronomic traits. A set of 16 SNPs were validated in nine soybean varieties, and seven SNPs were converted into CAPS. From functional gene association analysis, the marker CAPS282 on the 3'-UTR of gene Glyma07g03490 was identified as associated with 100-seed weight in soybean. The SNP discovery and CAPS markers conversion system developed in this study is fast and cost effective, and holds great promise for molecular-assisted breeding of soybean.

GDF9 as a candidate gene for prolificacy of Small Tail Han sheep

Growth differentiation factor 9 (GDF9) which controls the fecundity of Belclare, Cambridge, Santa Ines, Moghani, Ghezel and Thoka ewes was studied as a candidate gene for the prolificacy of Small Tail Han sheep. According to the sequence of ovine GDF9 gene, six pairs of primers were designed to detect single nucleotide polymorphisms of two exons of GDF9 gene in both high fecundity breed (Small Tail Han sheep) and low fecundity breed (Dorset sheep) by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP). Only the products amplified by primers 2-1 and 2-2 displayed polymorphisms. For primer 2-1, three genotypes (AA, AB and BB) were detected in both sheep breeds. Sequencing revealed one silent mutation (G477A) in exon 2 of GDF9 gene in the BB genotype in comparison with the AA, which was known as G3 mutation of GDF9 gene in Belclare and Cambridge ewes. The relationship of least squares means for litter size was AA > AB > BB in Small Tail Han sheep (P > 0.05). For primer 2-2, two genotypes (CC and CD) were detected in both sheep breeds. Sequencing revealed one novel single nucleotide mutation (G729T) in exon 2 of GDF9 gene in the CD genotype in comparison with the CC, which resulted in an amino acid change (Gln243His). The ewes with mutation heterozygous genotype CD had 0.77 (P < 0.01) lambs more than those with wild type CC in Small Tail Han sheep. These results preliminarily indicated that allele D of GDF9 gene was a potential genetic marker for improving litter size in Small Tail Han sheep.

Polymorphisms of caprine GDF9 gene and their association with litter size in Jining Grey goats

The exons 1, 2 and flanking region of growth differentiation factor 9 (GDF9) gene in five randomly selected does of Jining Grey, Boer and Liaoning Cashmere goats were amplified and analyzed. Thirteen nucleotide differences were identified in GDF9 gene between sheep (AF078545) and goats. Four SNPs (G3288A in intron 1, G423A, A959C [Gln320Pro] and G1189A [Val397Ile] in exon 2) were detected in four goat breeds with different prolificacy, in which G3288A was a new SNP in goats. The results showed that loci 3288, 423 and 1189 in Boer goats, loci 3288 and 423 in Guizhou White goats, loci 423 and 1189 in Liaoning Cashmere goats were all in complete linkage disequilibrium (D' = 1, r (2) = 1), respectively. In moderate (Boer goat) and low prolificacy (Liaoning Cashmere goat) breeds, linkage analysis indicated that there were more fervent linkage disequilibrium among loci 3288, 423 and 1189 than high prolificacy (Jining Grey and Guizhou White goats) breeds. For the 959 locus, the genotype distribution showed obvious difference between high prolificacy breeds and moderate or low prolificacy breeds (P < 0.05 or P < 0.01). The Jining Grey goat does with genotype CC or AC had 0.81 (P < 0.01) or 0.63 (P < 0.01) kids more than those with genotype AA, respectively. The present study preliminarily showed an association between allele C at 959 locus of GDF9 gene and high litter size in Jining Grey goats. These results provide further evidence that the GDF9 gene may be significantly correlated with high prolificacy in goats.