Dominant Allele Research Articles

Transgressive Segregation for Seed Protein in an Inter-specific Cajanus Cross

Three inter-specific Cajanus crosses were assessed for their intra-population variation for protein content. In the unselected F7 bulk population of a cross involving a wild species (Cajanus scarabaeoides) and an early maturing cultivar, “Baigani,” the transgressive segregation for both high as well as low protein contents was observed. The high protein (35.6%) transgressive segregant produced 24% more protein than the wild species donor parent (28.7%). Similarly, the low-protein (18.8%) transgressive segregant had 17% less protein than the low-protein parent (22.7%). It is concluded that the parents of this cross carried different sets of dominant and recessive protein-controlling alleles; their complementary and/or additive gene effects produced these transgressive segregants.

Can insecticide resistance increase malaria transmission? A genetics-epidemiology mathematical modeling approach.

The great successes recorded in the fight against malaria over the last two decades, resulting from the wide scale implementation of insecticide-based interventions in malaria-endemic areas, has prompted a renewed global effort to eradicate malaria. The widespread emergence of insecticide resistance in the population of adult female malaria mosquitoes is considered to pose a potential challenge to such effort. In this study, we address one of the key questions in malaria ecology, namely whether or not insecticide resistance increase malaria transmission. We developed a genetics-epidemiology modeling framework that incorporates a detailed genotype structure of the gene that confers insecticide resistance in mosquitoes, malaria epidemiology in mosquitoes and humans (stratified based on whether or not they are protected by Long-lasting insecticide-treated nets (LLINs) indoors), genotype-specific mosquito repellance property of LLINs and mosquito biting behavior (indoor and outdoor bites). Conditions for the existence and local asymptotic stability of the various disease-free equilibria (by genotype) of the resulting genetic-epidemiology model are derived. This study identifies four parameters of the model that play a crucial role on quantifying the impact of insecticide resistance on malaria transmission, namely the parameters related to the level of the dominance of the resistant allele in heterozygous mosquitoes, the coverage of long-lasting insecticidal nets in the community, the probability of endophilic mosquitoes to successfully take a bloodmeal indoors and the proportion of new adult mosquitoes that are endophilic. We showed that, depending on the values of these four identified parameters, insecticide resistance can increase, decrease, or have no effect on malaria transmission. Our simulations show that malaria eradication can indeed be achieved using the currently-available chemical insecticides, even in the wake of the prevailing widespread insecticide resistance in malaria-endemic areas, if the insecticide-based interventions implemented can result in the attainment of the optimal values of the four identified parameters in malaria-endemic areas.

Flax seed and flower color inheritance is more complicated than once thought

AbstractFlower and seed color are two characteristics of flax (Linum usitatissimum L.) where the mode of inheritance can be obscured by different genetic backgrounds. In this study, eight genetically diverse genotypes of flax with pairwise contrasting seed and flower colors were carefully selected from a large diversity panel and crossed in all directions (56 crosses). The mode of inheritance of seed and flower color was studied in F1, F2, and F3 generations during 2017–2020. Segregation patterns in F1 and F2 generations indicated that seed color is primarily determined by maternal genotype, but parents’ genetic constitution finally defines character expression. Segregation analysis in the F3 generation indicated that seed color is governed by three loci designated as G, D, and Y1. Brown seed color was produced by the recessive allele of the Y1 locus and dominant alleles of the G and D loci (GGDDy1y1). The yellow seed color was attributed to the homozygous condition of two recessive genes and one dominant gene (ggDDy1y1 and GGddy1y1) or the homozygous condition of three dominant genes (GGDDY1Y1). Flower color was found to be controlled by three loci assigned as B1, B2, and C′, independent of the ones for seed color. The blue flower is governed by dominant alleles at all three loci, while homozygous recessive at any of the three loci will result in a white flower. Segregating ratios of 3:1, 9:7, 13:3, and 27:37 blue to white flowers suggested different epistatic interactions between these loci, including duplicate‐recessive and dominant‐recessive states.

Identification and fine mapping of PmNJ3946 for powdery mildew resistance in einkorn wheat

Powdery mildew caused by Blumeria graminis f. sp. tritici (Bgt) is a destructive wheat disease. Although it can be easily overcome by deployment of resistance genes, the resistance is often quickly compromised by pathogen virulence. Thus, exploration and characterization of new resistance genes is always ongoing. Line NJ3946 derived from a cross of einkorn wheat accessions TA2032 and M389 showed resistance to powdery mildew. Inheritance analysis of an F2 population derived from a cross of NJ3946 and M389 suggested that the resistance was conferred by a dominant allele. With polymorphic markers identified through bulked segregant analysis (BSA), this gene was mapped to a novel locus on chromosome 3A, and was designated as PmNJ3946. Bulked segregant RNA-seq analysis (BSR-seq) was conducted to obtain more closely linked markers, which allowed delimitation of the PMNJ3946 locus to a 0.9 cM interval covering a physical distance of less than 1 Mb. PMNJ3946 was flanked by Xwgrc5153 and SNP-derived marker CHS21_3A008915069, and co-segregated with SNP-derived markers CHS21_3A008939814 and CHS21_3A008943175. The PmNJ3946 discovery expands the diversity of powdery mildew resistance genes and is useful for wheat breeding.

Identification of inbred lines harbouring favourable dominant alleles not present in the parents of three elite maize (Zea mays L.) single cross hybrids

Identification of inbred lines harbouring favourable dominant alleles not present in the parents of three elite maize (Zea mays L.) single cross hybrids

Mass-spectrometric analysis of APOB polymorphism rs1042031 (G/T) and its influence on serum proteome of coronary artery disease patients: genetic-derived proteomics consequences.

Genetic polymorphisms of apolipoprotein B gene (APOB) may result into serum proteomic perturbance in Coronary Artery Disease (CAD). The current case-control cohort of Pakistani subjects was designed to analyze the genetic influence of APOB rs1042031, (G/T) genotype on serum proteome. Subjects were categorized into two groups: CAD patients (n = 480) and healthy individuals (n = 220). For genotyping, tetra ARMS-PCR was carried out and validated through sequencing, whereas LC/MS-based proteomic analysis of serum samples was performed through label-free quantification. In initial step of genotyping, the frequencies of each genotype GG, GT, and TT were 70%, 27%, and 30% in CAD patients, while in control group, the subjects were 52%, 43%, and 5%, respectively, in CAD patients. The genotypic frequencies in patients vs. control groups found significantly different (p = 0.004), and a strong association of dominant alleles GG with the CAD was observed in both dominant (OR: 2.4 (1.71-3.34), p = 0.001) and allelic genetic models (OR: 2.0 (1.45-2.86), p = 0.001). In second step of label-free quantitation, a total of 40 significant proteins were found with altered expression in CAD patients. The enriched Gene Ontology (GO) terms of molecular functions and pathways of these protein showed upregulated pathways as follows: chylomicron remodeling and assembly, complement cascade activation, plasma lipoprotein assembly, apolipoprotein-A receptor binding, and metabolism of fat-soluble vitamins in G allele carrier of rs1042031 (G > T) vs. mutant T-allele carriers. This study provides better understanding of CAD pathobiology by proteogenomics of APOB. It evidences the influence of APOB rs1042031-dominant (GG) genotype with CAD patients.

Association of mycoplasma pneumoniae and (rs9271366) HLA-DRB1gene polymorphism with the immune susceptibility to rheumatoid arthritis

Abstract Background: Rheumatoid arthritis (RA) is a chronic, inflammatory disease that affects the immune system. The primary cause of RA is unknown, but there is evidence that genetic and environmental factors also contribute to the development of the disease. Objectives: This study aimed to illustrate the relationship between the RA and Mycoplasma pneumoniae. Materials and Methods: The work was performed on 50 RA patients of various ages, ranging from 25 to 75 years of age, who were treated at the rheumatology clinic of the city of Medical Marjan between February 2022 to October 2022.Blood samples were used for DNA extraction. HLA-DRB1, IL-6 and mycoplasma were detected by enzyme-linked immunosorbent assay (ELISA). Results: The results showed that compared with RA patients not infected with Mycoplasma pneumoniae and healthy subjects, serum IL-6 concentration was significantly increased in RA patients infected with Mycoplasma pneumoniae. The results showed that serum concentrations of HLADRB1 were significantly elevated in RA patients infected with M. pneumoniae compared with RA patients not infected with M. pneumoniae and healthy subjects. Conclusions: In HLA-DRB1 the SNP rs9271366 was significantly associated with RA and G allele represent as dominant pathogenic allele in which the individual that carry GG and AG genotype have more susceptibility to mycoplasma infection than subjects that carry AA genotype (P = 0.036).

Expression and inheritance of performance constituents and seed color in winter rye

Purpose. To establish peculiarities of inheritance of major breeding traits in lines - parents of winter rye hybrids; to assess the effectiveness of creating starting material for heterotic winter rye breeding based on lines - donors of purple seed color and a set of valuable economic characteristics. Material and methods. The experiments were conducted in the fields of Verkhniachka Experimental Breeding Station of the Institute of Bioenergy Crops and Sugar Beet (Verkhniachka EBS IBCSB) of NAAS of Ukraine (Umanskyi District of Cherkassy Region) in 2021-2022. The following F1 and F2 simple hybrids were studied: l.471 x l.44 and l.471 x l.4351H.4-1-22. F1 hybrids were sown manually in single-row sections of 1.5 m long by wide-row method (interrow distance = 25–30 cm) to a depth of 3–4 cm in 2020. The sowing design was as follows: female form – F1 – male form, using the female and male forms as references. All fully ripened plants were harvested with roots. For structural analysis, 25 plants of the hybrids, female and male forms were taken; they were evaluated for the following morphological features: plant height (PH), the productive shoot number (PSN), and spike length (SL). We analyzed such performance constituents as the flower number per spike (FMS), kernel number per spike (KNP), kernel weight per spike (KWS), kernel weight per plant (KWP), and thousand kernel weight (TKW). During the growing period, the phases of plant growth and development were monitored. Correspondence of the observed ratio of phenotypic classes to the theoretical one in F2 was assessed by the χ2 test. Results and discussion. Various forms from a genetic collection, carriers of dominant and recessive alleles of one or several marker traits were used as the starting material to explore expression and inheritance of morphological traits. Hybrid combination No. 16/17–743/18 (line 471) with purple seeds, which had been created by selection and self-pollination (inbreeding), was crossed with donors of the dominant ‘short stem’ trait with wild-type (light) color of seeds, l.44 and l.4351H.4-1-22. In F1 hybrids, the quantitative constituents of the plant performance, in particular the productive shoot number, flower number per spike, kernel number per spike, kernel weight per spike, and kernel weight per plant were higher than the parents’ mean values. High degree of dominance indicated that these traits were inherited by dominance and overdominance. In F2 hybrids, dihybrid segregation into genotypes with different colors was observed: purple due to pigments in the caryopsis coat, intermediate and wild-type color of the aleurone layer, with greater number of wild-type plants. The purple color of the caryopsis in the parental lines, l.44 and l.4351H.4-1-22, turned out to be recessive relative to the wild-type color, but at the same time it was dominant in l.471 / l.44 relative to intermediate color, and in l.4351H.4-1-22, on the contrary, it was recessive in relation to intermediate color. Epistasis in l.471 / l.44 was seen in the following sequence: wild-type ˃ purple ˃ intermediate, while in l.471 / l.4351H.4-1-22 the sequence differed: wild-type ˃ intermediate ˃ purple. Conclusions. Regardless of the genotypes of winter rye lines with colored and wild-type seeds included in crossings, the purple color of seeds showed a monogenic recessive inheritance.

A Million-Cow Genome-Wide Association Study of Three Fertility Traits in U.S. Holstein Cows.

A genome-wide association study (GWAS) of the daughter pregnancy rate (DPR), cow conception rate (CCR), and heifer conception rate (HCR) using 1,001,374-1,194,736 first-lactation Holstein cows and 75,140-75,295 SNPs identified 7567, 3798, and 726 additive effects, as well as 22, 27, and 25 dominance effects for DPR, CCR, and HCR, respectively, with log10(1/p) > 8. Most of these effects were new effects, and some new effects were in or near genes known to affect reproduction including GNRHR, SHBG, and ESR1, and a gene cluster of pregnancy-associated glycoproteins. The confirmed effects included those in or near the SLC4A4-GC-NPFFR2 and AFF1 regions of Chr06 and the KALRN region of Chr01. Eleven SNPs in the CEBPG-PEPD-CHST8 region of Chr18, the AFF1-KLHL8 region of Chr06, and the CCDC14-KALRN region of Chr01 with sharply negative allelic effects and dominance values for the recessive homozygous genotypes were recommended for heifer culling. Two SNPs in and near the AGMO region of Chr04 that were sharply negative for HCR and age at first calving, but slightly positive for the yield traits could also be considered for heifer culling. The results from this study provided new evidence and understanding about the genetic variants and genome regions affecting the three fertility traits in U.S. Holstein cows.

Allelic expression of AhNSP2-B07 due to parent of origin affects peanut nodulation.

Legumes are well-known for establishing a symbiotic relationship with rhizobia in root nodules to fix nitrogen from the atmosphere. The nodulation signaling pathway 2 (NSP2) gene plays a critical role in the symbiotic signaling pathway. In cultivated peanut, an allotetraploid (2n = 4x = 40, AABB) legume crop, natural polymorphisms in a pair of NSP2 homoeologs (Na and Nb) located on chromosomes A08 and B07, respectively, can cause loss of nodulation. Interestingly, some heterozygous (NBnb) progeny produced nodules, while some others do not, suggesting non-Mendelian inheritance in the segregating population at the Nb locus. In this study, we investigated the non-Mendelian inheritance at the NB locus. Selfing populations were developed to validate the genotypical and phenotypical segregating ratios. Allelic expression was detected in roots, ovaries, and pollens of heterozygous plants. Bisulfite PCR and sequencing of the Nb gene in gametic tissue were performed to detect the DNA methylation variations of this gene in different gametic tissues. The results showed that only one allele at the Nb locus expressed in peanut roots during symbiosis. In the heterozygous (Nbnb) plants, if dominant allele expressed, the plants produced nodules, if recessive allele expressed, then no nodules were produced. qRT-PCR experiments revealed that the expression of Nb gene in the ovary was extremely low, about seven times lower than that in pollen, regardless of genotypes or phenotypes of the plants at this locus. The results indicated that Nb gene expression in peanut depends on the parent of origin and is imprinted in female gametes. However, no significant differences of DNA methylation level were detected between these two gametic tissues by bisulfite PCR and sequencing. The results suggested that the remarkable low expression of Nb in female gametes may not be caused by DNA methylation. This study provided a unique genetic basis of a key gene involved in peanut symbiosis, which could facilitate understanding the regulation of gene expression in symbiosis in polyploid legumes.

Comprehensive Genotyping and Phenotyping Analysis of GUCY2D-Associated Rod- and Cone-Dominated Dystrophies

To describe the genetic and clinical spectrum of GUCY2D-associated retinopathies and to accurately establish their prevalence in a large cohort of patients. Retrospective case series. Institutional study of 47 patients from 27 unrelated families with retinal dystrophies carrying disease-causing GUCY2D variants from the Fundación Jiménez Díaz hospital dataset of 8000 patients. Patients underwent ophthalmological examination and molecular testing by Sanger or exome sequencing approaches. Statistical and principal component analyses were performed to determine genotype-phenotype correlations. Four clinically different associated phenotypes were identified: 66.7% of families with cone/cone-rod dystrophy, 22.2% with Leber congenital amaurosis, 7.4% with early-onset retinitis pigmentosa, and 3.7% with congenital night blindness. Twenty-three disease-causing GUCY2D variants were identified, including 6 novel variants. Biallelic variants accounted for 28% of patients, whereas most carried dominant alleles associated with cone/cone-rod dystrophy. The disease onset had statistically significant differences according to the functional variant effect. Patients carrying GUCY2D variants were projected into 3 subgroups by allelic combination, disease onset, and presence of nystagmus or night blindness. In contrast to patients with the most severe phenotype of Leber congenital amaurosis, 7 patients with biallelic GUCY2D had a later and milder rod form with night blindness in infancy as the first symptom. This study represents the largest GUCY2D cohort in which 4 distinctly different phenotypes were identified, including rare intermediate presentations of rod-dominated retinopathies. We established that GUCY2D is linked to about 1% of approximately 3000 molecularly characterized families of our cohort. All of these findings are critical for defining cohorts for inclusion in future clinical trials.

Микросателлитные локусы в генетической оценке плюсовых деревьев Pinus sylvestris L.

In this study, a comparative analysis was performed to estimate the genetic diversity levels of Pinus sylvestris L. in 49 seed orchards of I generation and progeny test plantings using 4-nucleus microsatellite loci. The seed orchards are located in the Petrozavodsk and Zaonezhye regions of the Republic of Karelia. The progeny trials were created by half-sibling seed progenies of the clones in the Petrozavodsk seed orchard. Micro-Checker software was used to identify null alleles and exclude genotyping errors. Coefficients of genetic originality were determined by examining the genetic structure of breeding objects in relation to the proportion between the rare and the dominant alleles for each selected tree. A major part of the rarest alleles (27.3–37.0 %) and a small fraction of the most common alleles (3.3–14.8 %) were detected for the distinct range of the pine trees in both seed orchards and test cultures. The largest number (40) of all identified alleles (51) was found in the Petrozavodsk seed orchard. The Hardy-Weinberg test comparing allele rates to expectational values showed a lack of heterozygotes in each category of the empirical substances. The selected material also had high levels of allelic and genetic diversity. The average number of alleles per locus ranged from 7.75 to 10.50. The average effective number was from 5.00 to 6.54. The observed heterozygosity varied from 0.60 to 0.70. The expected heterozygosity was 0.63–0.71. The numerical deviations were statistically insignificant. The AMOVA molecular dispersion result was 5 %, indicating the absence of significant genetic differentiation between the breeding objects. The heterozygote deficiency was caused not only by the presence of null alleles, but also by the selection. Namely, the set of alleles in the experimental material, randomly selected from a limited number of genotypes (clones), may differ from the natural population. The high level of the rarest alleles in the given range of the pine trees can also be explained as a selection effect. The results obtained in this study are important for creating breeding objects with higher genetic value. For citation: Ilinov A.A., Raevsky B.V. Genetic Evaluation by Microsatellite Loci of Pinus sylvestris L. Plus Trees. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 3, pp. 48–68. (In Russ.). https://doi.org/10.37482/0536-1036-2023-3-48-68

Genetic Mapping, Candidate Gene Identification and Marker Validation for Host Plant Resistance to the Race 4 of Fusarium oxysporum f. sp. cubense Using Musa acuminata ssp. malaccensis.

Fusarium wilt of banana is a devastating disease that has decimated banana production worldwide. Host resistance to Fusarium oxysporum f. sp. Cubense (Foc), the causal agent of this disease, is genetically dissected in this study using two Musa acuminata ssp. Malaccensis segregating populations, segregating for Foc Tropical (TR4) and Subtropical (STR4) race 4 resistance. Marker loci and trait association using 11 SNP-based PCR markers allowed the candidate region to be delimited to a 12.9 cM genetic interval corresponding to a 959 kb region on chromosome 3 of 'DH-Pahang' reference assembly v4. Within this region, there was a cluster of pattern recognition receptors, namely leucine-rich repeat ectodomain containing receptor-like protein kinases, cysteine-rich cell-wall-associated protein kinases, and leaf rust 10 disease-resistance locus receptor-like proteins, positioned in an interspersed arrangement. Their transcript levels were rapidly upregulated in the resistant progenies but not in the susceptible F2 progenies at the onset of infection. This suggests that one or several of these genes may control resistance at this locus. To confirm the segregation of single-gene resistance, we generated an inter-cross between the resistant parent 'Ma850' and a susceptible line 'Ma848', to show that the STR4 resistance co-segregated with marker '28820' at this locus. Finally, an informative SNP marker 29730 allowed the locus-specific resistance to be assessed in a collection of diploid and polyploid banana plants. Of the 60 lines screened, 22 lines were predicted to carry resistance at this locus, including lines known to be TR4-resistant, such as 'Pahang', 'SH-3362', 'SH-3217', 'Ma-ITC0250', and 'DH-Pahang/CIRAD 930'. Additional screening in the International Institute for Tropical Agriculture's collection suggests that the dominant allele is common among the elite 'Matooke' NARITA hybrids, as well as in other triploid or tetraploid hybrids derived from East African highland bananas. Fine mapping and candidate gene identification will allow characterization of molecular mechanisms underlying the TR4 resistance. The markers developed in this study can now aid the marker-assisted selection of TR4 resistance in breeding programs around the world.

Rethinking (again) Hardy-Weinberg and genetic drift in undergraduate biology.

Designing effective curricula is challenging. Content decisions can impact both learning outcomes and student engagement. As an example consider the place of Hardy-Weinberg equilibria (HWE) and genetic drift calculations in introductory biology courses, as discussed by Masel (2012). Given that population genetics, "a fairly arcane speciality", can be difficult to grasp, there is little justification for introducing introductory students to HWE calculations. It is more useful to introduce them to the behavior of alleles in terms of basic features of biological systems, and that in the absence of selection recessive alleles are no "weaker" or preferentially lost from a population than are dominant alleles. On the other hand, stochastic behaviors, such as genetic drift, are ubiquitous in biological systems and often play functionally significant roles; they can be introduced to introductory students in mechanistic and probabilistic terms. Specifically, genetic drift emerges from the stochastic processes involved in meiotic chromosome segregation and recombination. A focus on stochastic processes may help counteract naive bio-deterministic thinking and can reinforce, for students, the value of thinking quantitatively about biological processes.

Development of novel gene-based markers for waxy1 gene and their validation for exploitation in molecular breeding for enhancement of amylopectin in maize.

Waxy corn possessing high amylopectin is widely employed as an industrial product. Traditional corn contains ~ 70-75% amylopectin, whereas waxy corn with the mutant waxy1 (wx1) gene possesses ~ 95-100% amylopectin. Marker-assisted breeding can greatly hasten the transfer ofthe wx1 allele into normal corn. However, the available gene-based marker(s) for wx1 are not always polymorphic between recipient and donor parents, thereby causing a considerable delay in the molecular breeding program. Here, a 4800bp sequence ofthe wx1 gene was analyzed among seven wild-type and seven mutant inbreds employing 16 overlapping primers. Three polymorphisms viz., 4bp InDel (at position 2406bp) in intron-7 and two SNPs (C to A at position 3325bp in exon-10 and G to T at position 4310bp in exon-13) differentiated the dominant (Wx1) and recessive (wx1) allele. Three breeder-friendly PCR markers (WxDel4, SNP3325_CT1, and SNP4310_GT2) specific to InDel and SNPs were developed. WxDel4 amplified 94bp among mutant-type inbreds, while 90bp was amplified among wild-type inbreds. SNP3325_CT1 and SNP4310_GT2 revealed the presence-absence polymorphisms with an amplification of 185bp and 189bp of amplicon, respectively. These newly developed markers showed 1:1 segregation in both BC1F1 and BC2F1 generations, while 1:2:1 segregation was observed in BC2F2. The recessive homozygotes (wx1wx1) of BC2F2 identified by the markers possessed significantly higher amylopectin (97.7%) compared to the original inbreds (Wx1Wx1: 72.7% amylopectin). This is the first report of novel wx1 gene-based markers. The information generated here would help in accelerating the development of waxy maize hybrids.

Autosomal Dominant Non-Syndromic Hearing Loss (DFNA): A Comprehensive Narrative Review.

Autosomal dominant non-syndromic hearing loss (HL) typically occurs when only one dominant allele within the disease gene is sufficient to express the phenotype. Therefore, most patients diagnosed with autosomal dominant non-syndromic HL have a hearing-impaired parent, although de novo mutations should be considered in all cases of negative family history. To date, more than 50 genes and 80 loci have been identified for autosomal dominant non-syndromic HL. DFNA22 (MYO6 gene), DFNA8/12 (TECTA gene), DFNA20/26 (ACTG1 gene), DFNA6/14/38 (WFS1 gene), DFNA15 (POU4F3 gene), DFNA2A (KCNQ4 gene), and DFNA10 (EYA4 gene) are some of the most common forms of autosomal dominant non-syndromic HL. The characteristics of autosomal dominant non-syndromic HL are heterogenous. However, in most cases, HL tends to be bilateral, post-lingual in onset (childhood to early adulthood), high-frequency (sloping audiometric configuration), progressive, and variable in severity (mild to profound degree). DFNA1 (DIAPH1 gene) and DFNA6/14/38 (WFS1 gene) are the most common forms of autosomal dominant non-syndromic HL affecting low frequencies, while DFNA16 (unknown gene) is characterized by fluctuating HL. A long audiological follow-up is of paramount importance to identify hearing threshold deteriorations early and ensure prompt treatment with hearing aids or cochlear implants.

Genetic Preference for Sweet Taste in Mothers Associates with Mother-Child Preference and Intake.

Taste perception is a well-documented driving force in food selection, with variations in, e.g., taste receptor encoding and glucose transporter genes conferring differences in taste sensitivity and food intake. We explored the impact of maternal innate driving forces on sweet taste preference and intake and assessed whether their children differed in their intake of sweet foods or traits related to sweet intake. A total of 133 single nucleotide polymorphisms (SNPs) in genes reported to associate with eating preferences were sequenced from saliva-DNA from 187 mother-and-child pairs. Preference and intake of sweet-, bitter-, sour-, and umami-tasting foods were estimated from questionnaires. A total of 32 SNP variants associated with a preference for sweet taste or intake at a p-value < 0.05 in additive, dominant major, or dominant minor allele models, with two passing corrections for multiple testing (q < 0.05). These were rs7513755 in the TAS1R2 gene and rs34162196 in the OR10G3 gene. Having the T allele of rs34162196 was associated with higher sweet intake in mothers and their children, along with a higher BMI in mothers. Having the G allele of rs7513755 was associated with a higher preference for sweets in the mothers. The rs34162196 might be a candidate for a genetic score for sweet intake to complement self-reported intakes.

Non-vernalization requirement for flowering in Brassica rapa conferred by a dominant allele of FLOWERING LOCUS T

We identified and characterized a dominant FT allele for flowering without vernalization in Brassica rapa, while demonstrating its potential for deployment in breeding to accelerate flowering in various Brassicaceae crops. Controlling the timing of flowering is key to improving yield and quality of several agricultural crops including the Brassicas. Many Brassicaceae crops possess a conserved flowering mechanism in which FLOWERING LOCUS C (FLC) represses the transcription of flowering activators such as FLOWERING LOCUS T (FT) during vernalization. Here, we employed genetic analysis based on next-generation sequencing to identify a dominant FT allele, BraA.FT.2-C, for flowering in the absence of vernalization in the Brassica rapa cultivar 'CHOY SUM EX CHINA 3'. BraA.FT.2-C harbors two large insertions upstream of its coding region and is expressed without vernalization, despite FLC expression. We show that BraA.FT.2-C offers an opportunity to introduce flowering without vernalization requirement into winter-type brassica crops, including B. napus, which have many functional FLC paralogs. Furthermore, we demonstrated the feasibility of using B. rapa harboring BraA.FT.2-C as rootstock for grafting to induce flowering in radish (Raphanus sativus), which requires vernalization for flowering. We believe that the ability of BraA.FT.2-C to overcome repression by FLC can have significant applications in brassica crops breeding to increase yields by accelerating or delaying flowering.

Development and identification of molecular markers of GhHSP70-26 related to heat tolerance in cotton

Heat stress significantly affect plant growth and development, which is an important factor contributing to crop yield loss. However, heat shock proteins (HSPs) in plants can effectively alleviate cell damage caused by heat stress. In order to rapidly and accurately cultivate heat-tolerant cotton varieties, this study conducted correlation analysis between heat tolerance index and insertion/deletion (In/Del) sites of GhHSP70-26 promoter in 39 cotton materials, so as to find markers related to heat tolerance function of cotton, which can be used in molecular marker-assisted breeding. The results showed the natural variation allele (Del22 bp) type at −1590 bp upstream of GhHSP70-26 promoter (haplotype2, Hap2) in cotton (Gossypium spp.) promoted GhHSP70-26 expression under heat stress. The relative expression level of GhHSP70-26 of M−1590−Del22 cotton materials were significantly higher than that of M−1590−In type cotton materials under heat stress (40 ℃). Also, M−1590−Del22 material had lower conductivity and less cell damage after heat stress, indicating that it is a heat resistant cotton material. The Hap1 (M−1590−In) promoter was mutated into Hap1del22, and Hap1 and Hap1del22 were fused with GUS to transform Arabidopsis thaliana. Furthermore, Hap1del22 promoter had higher induction activity than Hap1 under heat stress and abscisic acid (ABA) treatment in transgenic Arabidopsis thaliana. Further analysis confirmed that M−1590−Del22 was the dominant heat-resistant allele. In summary, these results identify a key and previously unknown natural variation in GhHSP70-26 with respect to heat tolerance, providing a valuable functional molecular marker for genetic breeding of cotton and other crops with heat tolerance.

Genetic monitoring of sterlet juveniles (Acipenser ruthenus) in the Volga river

The aim of the work was to carry out genetic monitoring of the natural reproduction of juveniles (larvae and underyearlings) of sterlet (Acipenser ruthenus Linnaeus, 1958), caught in the middle and lower spawning zones of the Volga River for the period 2021–2022, which is necessary and relevant in the context of a decrease in the number of sturgeon species of fish. The study of fish was carried out according to five nuclear markers and a fragment of the control region of mitochondrial DNA.According to the results of microsatellite analysis, sterlet individuals were characterized by species-specific dominant alleles and high values of the main indicators of genetic diversity: the number of alleles, allelic diversity and heterozygosity, and a slight deficit of heterozygotes was noted. By analyzing of the nucleotide sequences of the mtDNA D-loop region a high level of diversity of maternally inherited haplotypes was revealed, reflecting the number of females involved in natural reproduction. According to the monitoring data, no differences in the distribution and number of identified variants of the D-loop region were registered in the interannual aspect. During the study period, 48 sterlet mitochondrial haplotypes were recorded, of which 18 mtDNA variations were unique, occurring in the Volga-Caspian fishery basin. In the study of sterlet larvae by molecular genetic methods in the Volga River was revealed the process of hybridization between stellate sturgeon and sterlet (Acipenser stellatus × Acipenser ruthenus).