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Biochemical Genetics (v.42, #1-2)
Genetic Diversity and Relationship of Yunnan Native Cattle Breeds and Introduced Beef Cattle Breeds by Ying Yu; Lin-Sheng Lian; Ji-Kun Wen; Xian-Wei Shi; Fang-Xian Zhu; Long Nie; Ya-Ping Zhang (pp. 1-9).
In this study, random amplified polymorphic DNA (RAPD) analysis was used to estimate genetic diversity and relationship in 134 samples belonging to two native cattle breeds from the Yunnan province of China (DeHong cattle and DiQing cattle) and four introduced beef cattle breeds (Brahman, Simmental, MurryGrey, and ShortHorn). Ten primers were used, and a total of 84 bands were scored, of which 63 bands (75.0%) were polymorphic. The genetic distance matrix was obtained by proportions of shared fragment. The results indicate that the Yunnnan DeHong cattle breed is closely related to the Brahman (Bos indicus), and the Yunnan DiQing cattle breed is closely related to the Simmental, ShortHorn, and MurryGrey (Bos taurus) breeds. Our results imply that Bos indicus and Bos taurus were the two main origins of Yunnan native cattle. The results also provide the basic genetic materials for conservation of cattle resources and crossbreeding of beef cattle breeds in South China.
Keywords: native cattle breeds; beef cattle breeds; RAPD; genetic diversity; relationship
Characterization of Two SNPs (Single Nucleotide Polymorphisms) in the Porcine INSL3 Gene and Their Exclusion as a Common Genetic Basis of Hernia Inguinalis in Pigs by Christoph Knorr; Helge Täubert; Ulrike Peters; Bertram Brenig (pp. 11-19).
The INSL3 gene encoding Leydig cell insulin-like hormone is an important candidate gene for congenital disorders of the reproductive tract in pigs. Comparative sequencing using phenotypically hernia inguinalis affected and unaffected animals showed that the porcine gene is remarkably conserved. No polymorphisms were found in the two exons or in the intron. Two single-nucleotide polymorphisms (SNPs) were detected in the promoter region (G-224A and A-164C) of the sequenced pigs and fast screening methods were developed for large scale studies. Some significant breed differences exist for allele frequencies at both SNPs in the INSL3 gene. Screening of the two SNPs in a population of hernia inguinalis affected full and half sib piglets (n = 223) revealed that the SNPs can be excluded as a common genetic basis for this congenital disorder in this pedigree.
Keywords: INSL3; pig; SNP; hernia inguinalis
Identification and Characterization of a Nitrate Transporter Gene in Neurospora crassa by Fei Gao-Rubinelli; George A. Marzluf (pp. 21-34).
The Neurospora crassa genome database was searched for sequence similarity to crnA, a nitrate transporter in Aspergillus nidulans. A 3.9-kb fragment (contig 3.416, subsequence 183190–187090) was cloned by PCR. The gene coding for this nitrate transporter was termed nit-10. The nit-10 gene specifies a predicted polypeptide containing 541 amino acids with a molecular mass of 57 kDa. In contrast to crnA, which is clustered together with niaD, encoding nitrate reductase, and niiA, encoding nitrite reductase, nit-10 is not linked to nit-3 (nitrate reductase), nit-6 (nitrite reductase), or to nit-2, nit-4 (both are positive regulators of nit-3), or nmr (negative regulator of nit-3) in Neurospora crassa. A nit-10 rip mutant failed to grow in the medium when nitrate (<10 mM) was used as the sole nitrogen source, but grew similarly to wild type when nitrate concentration was 10 mM or higher. In addition, it showed strong sensitivity to cesium in the presence of nitrate and resistance to chlorate in the presence of alanine, proline, or hypoxanthine. The expression of nit-10 required nitrate induction and was subject to repression by nitrogen metabolites such as glutamine. Expression of nit-10 also required functional products of nit-2 and nit-4. The half-life of nit-10 mRNA was determined to be approximately 2.5 min.
Keywords: Neurospora crassa ; nitrate transporter; nit-10 ; nitrogen metabolism
Microsatellite Variation in Red-Winged Blackbirds (Agelaius phoeniceus) by C. Lenney Williams; H. J. Homan; J. J. Johnston; G. M. Linz (pp. 35-41).
Territorial male red-winged blackbirds from five locations in the United States and Canada were genotyped using a suite of six microsatellite loci. Each population possessed unique alleles, but numbers of alleles per locus (range = 7.3–8.8) and expected multilocus heterozygosities (range = 0.76–0.80) were similar in all populations. Significant overall allele frequency differences were detected between some population pairs, and some pairwise F st values were significant (but small). However, F st among populations, although significant, was also small (0.009). Despite revealing low levels of population structure, the high multilocus polymorphism indicates these loci will be valuable in the genetic analysis of behavior and reproductive strategies in this species.
Keywords: red-winged blackbird; microsatellite; Agelaius phoeniceus
AFLP-Based Genetic Diversity and Its Comparison with Diversity Based on SSR, SAMPL, and Phenotypic Traits in Bread Wheat by J. K. Roy; M. S. Lakshmikumaran; H. S. Balyan; P. K. Gupta (pp. 43-59).
Data on AFLP (eight primer pairs) and 14 phenotypic traits, collected on 55 elite and exotic bread wheat genotypes, were utilized for estimations of genetic diversity. We earlier used these 55 genotypes for a similar study using SSRs and SAMPL. As many as 615 scorable AFLP bands visualized included 287 (46.6%) polymorphic bands. The phenotypic traits included yield and its component traits, as well as physiomorphological traits like flag leaf area. Dendrograms were prepared using cluster analysis based on Jaccard's similarity coefficients in case of AFLP and on squared Euclidean distances in case of phenotypic traits. PCA was conducted using AFLP data and a PCA plot was prepared, which was compared with clustering patterns in two dendrograms, one each for AFLP and phenotypic traits. The results were also compared with published results that included studies conducted elsewhere using entirely different wheat germplasm and our own SSR and SAMPL studies based on the same 55 genotypes used in the present study. It was shown that molecular markers are superior to phenotypic traits and that AFLP and SAMPL are superior to other molecular markers for estimation of genetic diversity. On the basis of AFLP analysis and keeping in view the yield performance and stability, a pair of genotypes (E3876 and E677) was recommended for hybridization in order to develop superior cultivars.
Keywords: AFLP; SAMPL; SSR; phenotypic data; bread wheat; diversity
Expression of Tropomyosin-Encoding Gene in the Kidney Depends on Functioning of Vasopressin Gene by Igor I. Khegay; Alexey V. Katokhin (pp. 61-67).
Brattleboro diabetes insipidus mutant rats and normal WAG rats were subjected to water loading or thirst during 3 days. It was found that tropomyosin-encoding gene expression has a tissue-specific pattern in the kidney. Northern blot and western blot analysis had shown that the main expression of Tpm3 3 takes place in the renal medulla, and its intensity differs in normal and mutant rats. The differences between mutants with an ineffective vasopressin synthesizing system and the rats having an intact vasopressin gene were more distinct under long-lasting dehydration. The ratio between renal medullary tropomyosin of Brattleboro and WAG lines of rats was 39.76±0.90 versus 18.29±0.86 under water loading, and 46.12±2.14 versus 13.83±0.66 in thirst.
Keywords: kidney; microfilaments; tropomyosin; vasopressin gene; diabetes insipidus