Super-Sweet Purple Sweetcorn: Breaking the Genetic Link

Purple-pericarp supersweet sweetcorn currently does not exist as a horticultural product. Purple pericarp comprises the outer layers of the kernel, with the purple pigment being produced by anthocyanin. Unlike the aleurone layer which can also be pigmented, the pericarp is maternal tissue. Although standard purple sweetcorn based on mutations such as sugary1 (su1) and sugary enhancer (se1) are in existence, the development of purple supersweet sweetcorn based on the widely used shrunken2 (sh2) gene mutation is much more challenging. This is because there is an extremely close genetic linkage between the supersweet shrunken-2 mutation and the anthocyanin biosynthesis gene, anthocyaninless-1 (a1). As distance between these two genes is only 0.1 cM, the development of purple supersweet sweetcorn depends on breaking this close genetic link, which occurs at a very low frequency of 1 in 1000 meiotic crossovers. To make this possible, we crossed a white supersweet variety (a1a1sh2sh2) with a purple-pericarp Peruvian maize (A1A1Sh2Sh2) to obtain an initial heterozygous hybrid (A1a1Sh2sh2). The hybrid seed was sown and subsequently self-pollinated to produce seed segregating for the double recessive homozygote, sh2sh2 (1 in 4). These kernels present a visually distinctive phenotype, characterised by the seed’s shrunken appearance. Approximately 2760 sh2sh2 seeds were separated and resown. Due to the low frequency of linkage breakage, the majority of these plants (~99.9%) produced supersweet white cobs (a1a1sh2sh2). Three plants (0.1%) however, produced supersweet purple cobs (A1a1sh2sh2), due to a single low-frequency linkage break. These cobs will form the basis for a purple-pericarp supersweet sweetcorn breeding program.

Living-Related Kidney Transplantation in a Patient with Juvenile Nephronophthisis

Nephronophthisis (NPHP) is an autosomal recessive disease manifesting as tubulointerstitial nephritis uniformly progressing to ESRD in approximately 5–10% patients in childhood. Living donor transplantation is the most beneficial mean of renal replacement therapy compared to other methods. However, living kidney donation is contraindicated in potential donor with diseases of autosomal dominant mode of inheritance potentially leading to kidney failure in future. On the other hand, autosomal recessive genetic kidney diseases, such as NPHP, are not usually contraindication to living kidney donation. Herein, we are reporting related living kidney transplantation with a family history of NPHP form 46-year-old mother (heterozygote) to 17-year-old daughter with (autosomal recessive homozygote) with focus on donor follow-up after nephrectomy.

Inheritance of Top Branching in Sunflower (Helianthus Annuus L.) Collection Samples

Aim of our research was to study the genetic diversity and establish the inheritance of top branching trait in the collection of 34 sunflower lines of the Institute of Oilseed Crops of the NAAS. Experiments were carried out in 2005–2016 according to classical cultivation methods, using manual castration, crossings, forced self-pollinating, isolation and visual assessment of the first and second generation of obtained descendants. The statistical reliability of the obtained ratio was confirmed by calculating the Pearson’s chi-squared test. Presence of two loci determining the inheritance of the branching trait in sunflower was established. In one locus, recessive alleles are responsible for manifestation of the branching trait. In the second locus, dominant alleles are responsible for the manifestation of the branching trait. In 23 lines of sunflower, it was established that a recessive homozygote for one gene causes phenotypical top and full branching. In 8 lines of the collection, full branching trait is due to the dominant allele of the gene. In the lines InK235, APS49, the presence of two genes was established, the dominant alleles of which determine full branching trait. In the APS56 line, full branching is controlled by the dominant alleles of three genes.

Inheritance of branching in sunflower (Helianthus annuus L.)

Aim. The purpose of our research was to study genetic diversity and establish the inheritance of the branching trait in the collection of sunflower lines of the Institute of Oilseeds of the National Academy of Sciences. Methods. 47 lines were used as a material for studying the genetics of the branching feature. Methods of crossing with pre-castration, self-pollination and analysis of offspring were used. Results. In 25 lines, a monogenic recessive control of the trait of the upper branching to the continuous branch was established. In 9 lines of the collection, the sign of continuous branching is due to the dominant allele of the gene. In two lines, the presence of two genes of the dominant alleles of which cause the sign of continuous branching is established. In 1 lines, the trait of continuous branching is controlled by the dominant alleles of the three genes. In 5 lines, the sign of the basal branch is due to the recessive homozygote of one gene b2. In 4 lines, the trait of the basal branch is due to the recessive homozygote for the two genes b3 and b4. Conclusions. In total, four genes are found in our collection, recessive alleles of which cause branching and three genes whose dominant alleles cause branching.Keywords: genetics, sunflower, branching, gene, inheritance.

Inheritance of Basal Branching in Sunflower

Collection of sunflower lines of the Institute of Oilseed Crops was studied based on its branching. Ten lines with the basal branching trait were identified. It was established that the inheritance of the basal branching is due to the recessive alleles of the genes. For lines InLD1240, Z1064, LD835, KG13, VIR130, KG13, LD4, basal branching trait is due to the recessive homozygote of one gene b2. In lines LD72/3, LD156, KG16, I2K2218, basal branching trait is due to the recessive homozygote of two genes b3 and b4. It was established that the genes determining basal branching are distributed in the offspring independently of the genes controlling the top branching.

The Protective Effect of Transcription Factor 7-Like 2 Risk Allele rs7903146 against Elevated Fasting Plasma Triglyceride in Type 2 Diabetes: A Meta-Analysis

Background. The results from published studies regarding association of transcription factor 7-like 2 (TCF7L2) variant rs7903146 with dyslipidemia have been conflicting and inconclusive.Methods. We carried out a meta-analysis that aimed to investigate the association of the rs7903146 variant with plasma lipid levels using electronic database and published studies. Data was extracted by a standard algorithm. Dominant, recessive, homozygote, and heterozygote comparison models were utilized.Results. 24 studies incorporating 52,785 subjects were included in this meta-analysis. Overall, the minor allele (T) was associated with lower risk for hypertriglyceridemia in subjects with type 2 diabetes (dominant model: SMD = −0.04, 95% CI (−0.08, 0.00),P= 0.048,Pheterogeneity= 0.47; recessive model: SMD = −0.10, 95% CI (−0.18, −0.02),P= 0.01,Pheterogeneity= 0.56). No association was found between minor (T) allele and plasma TC, LDL-c, or HDL-c levels in subjects with type 2 diabetes or metabolic syndrome (MetS) and no association was found between minor (T) allele and plasma TG levels in nondiabetic subjects.Conclusions. Our meta-analysis indicated the association between TCF7L2 rs7903146 polymorphism and low plasma triglyceride (TG) level in subjects with type 2 diabetes. No association was found between rs7903146 variant and plasma lipids in nondiabetic subjects.

Genetic polymorphism of blood potassium in goat belonging to the different breeds and subbreed in Mongolia

In the goats belonging to the different breeds and sub breed the genetic polymorphism at the determinant locus of blood potassium was revealed by flame spectrophotometer method. The kalemic systems, in those breeds were characterized by a polymorphism of middle level due to the existence of the two phenotypes and of three genotypes. The polymorphic character of this system is given by the distributional discontinuity of potassium ions in whole blood, the discontinuous space ranging were 10-34 m eq/L in the Mongolian native breed, 0.38-20.3 m eq/L in the Govigurbansaihan breed, 10.27- 15.8 m eq/ L in the AltainUlaan sub breed. The remarkable differences in the whole blood of potassium concentrations were recognized between Mongol and Govi-Gurban Saikhan breeds td=6.46 or (p<0.001), Govi-Gurban Saikhan and Altai ulaan (td=5.7) or (p<0.001). As this trait, the slight difference was revealed between Mongol and Altai ulaan breeds (td=1.87) or (p>0.05). The correlation of the trait was also high r=0.57 between these breeds. The animals with potassium ion concentration below the discontinuity space are of LK type and those with ionic concentration above the discontinuity space are of HK type. The blood potassium level is determined by two alleles; KL and Kh, being in incomplete dominance relationship; the allele K L, responsible for low potassium, is dominant compared to its recessive Kh allele which causes high levels of blood potassium. These two alleles at the Ks locus, located on an autosomal chromosome, determine three genotypes; KLKL (dominant homozygote), KLKh (heterozygote), and KhKh (recessive homozygote). In the Mongolian native breed the allele Kh was less frequent (20%) than its dominant KL (80%), in the Govi Gurban Saihan breed, the frequency of the alleles were also 5 %, 95% respectively. The phenotype LK (80%-100%) achieved a much higher frequency than the phenotype HK (5%-20%) in those breeds. Consequently, the recessive homozygosis and heterozygosis recorded in an equally frequency (50%, 50%) in the Mongolian native breed, instead, the frequency of recessive homozygosis were slightly higher than heterozygosis (66%>34%) in the Govi Gurban Saihan. DOI: http://dx.doi.org/10.5564/mjas.v11i2.217 Mongolian Journal of Agricultural Sciences Vol.11(2) 2013 pp.54-58

Adenohypophyseal response to hypophysiotropic hormones in male obese Zucker rats

Description of the recessive, homozygote obese Zucker rat (fafa) includes disorders of growth and reproduction. The aim of this study was to compare responsiveness of adenohypophyseal cells, obtained from male fafa rats and from their lean siblings, to growth hormone-releasing factor (GRF) and to luteinizing hormone-releasing hormone (LHRH). Pituitary cells were cultured for 4 days and were then challenged with either GRF-29 (the NH2-terminal 29 amino acid GRF peptide that expresses full biological activity of its parent 44 amino acid molecule) or [D-Trp6]LHRH (LHRH-A, an LHRH agonist). Medium was assayed for growth hormone (GH), luteinizing hormone (LH), and follicle-stimulating hormone (FSH) by radioimmunoassay. Dose-response curves were compared using the computer program ALLFIT. The median effective GRF-29 concentration (EC50) computed for hypophyseal cells cultured from lean animals (0.30 +/- 0.01 fM; means +/- SE of 4 experiments) was less (P less than 0.01) than that calculated for cells obtained from fafa rats (15.8 +/- 6.7 fM). In contrast, cells derived from lean littermates required a larger (EC50) concentration of LHRH-A than did gonadotrophs cultured from obese rats [58.2 +/- 1.2 vs. 10.7 +/- 1.2 pM (P less than 0.01) and 59.4 +/- 10.4 vs. 15.7 +/- 7.6 pM (P less than 0.05)] to secrete LH and FSH, respectively. Our data describe an attenuated pituitary response to GRF-29 and an enhanced response to LHRH-A in the fafa.

Induction of diploid gynogenesis in Atlantic salmon and rainbow trout using irradiated sperm and heat shock

Three experiments were carried out to investigate the possibility of producing inbred lines of Atlantic salmon (Salmo salar) and rainbow trout (Salmo gairdneri) by gynogenesis using irradiated sperm and heat shock. In experiment I, tolerance of eggs to heat shock was investigated. In experiment II, eggs were inseminated with irradiated sperm and effects of temperature level, duration of shock, and time from insemination to heat shock were investigated. Heat shock administered for 10 or 20 min during the first 30 min after insemination increased the frequency of gynogenetic fry. Time from insemination to heat shock did not influence the results. The highest frequencies of gynogenetic fry were produced when Atlantic salmon and rainbow trout eggs were heat shocked at 24 and 26 °C, respectively. In experiment III, eggs from albino rainbow trout (recessive homozygote for a depigmentation gene) were inseminated with irradiated sperm from wild-type coloured males and heat shocked. All fry produced in this experiment were of the yellow albino phenotype. It is concluded that induction of diploid gynogenesis by heat shock is a rapid and practical method of producing high numbers of inbred lines in Atlantic salmon and rainbow trout.

GENES CONTROLLING MATING-TYPE SPECIFICITY IN PARAMECIUM CAUDATUM: THREE LOCI REVEALED BY INTERSYNGENIC CROSSES

ABSTRACT In mating interactions in Paramecium caudatum, initial mating agglutination is strictly mating-type specific, but subsequent conjugating pair formation is not mating-type specific. Using this nonspecificity of pair formation, intersyngenic (intersibling species) pairs were induced by mixing four mating types of two different syngens. To distinguish intersyngenic pairs from intrasyngenic ones, the behavioral marker CNR (Takahashi 1979) was mainly used. Clones of intersyngenic hybrids showed high fertility and thus made feasible a genetic analysis of syngenic specificity of mating type. The syngenic specificities of E (even) mating types were found to be controlled by co-dominant multiple alleles at the Mt locus, and those of O (odd) mating types by interactions of co-dominant multiple alleles at two loci, MA and MB. Clones of heterozygotes express dual mating types. Mt is epistatic to MA and MB, and thus O mating types can be expressed only in the recessive homozygote (mt/mt) at the Mt locus. In addition, at least one allele each at the MA and MB loci must have a common syngen specificity for the expression of O types. Thus, when MA is homozygous for one syngen and MB is homozygous for another syngen, no mating type is expressed.