Journal of Genetics最新文献

Plant height and spikelet density are two important traits for wheat (Triticum aestivum L.) yield. The development of wheat mutants not only provides new genetic resources for wheat improvement but also facilitates our understanding of the molecular regulation of these traits. Previously, we obtained a mutant named dwarf and spike compactness (dsc) from wheat cultivar Guomai301 (wild type, WT) treated with ethyl methane sulphonate. This study investigates the heredity, mutated gene location, and the candidate gene of dsc. Highresolution chromosome painting analysis indicated that there were no visible structural variations in the mutant dsc. Genetic analysis indicated that the phenotype of dsc was controlled by a single dominant gene, named as dsc. The wheat 660 K single-nucleotide polymorphism (SNP) array and simple sequence repeat (SSR) marker assay were employed to map the mutated gene. A total of 984 SNPs were identified between the DNA bulks, among which, 492 SNPs were located on chromosome 5A in 580-680 Mb genomic region, which occupied 50% of the total SNPs. The gene dsc was mapped in a 33.4 Mb (625.7-659.1 Mb) region on chromosome arm 5AL, flanked by SSR markers Xbarc319 and Xgpw2136, where 5AQ is located. Sequences and expression patterns of 5AQ from WTand dsc were compared. The two 5AQs had a SNP (G>A) in the miR172 binding site. A dCAPS marker was developed based on the SNP, and the marker was cosegregated with the mutated phenotypes in a F_2:3 population derived from the cross dsc x Chinese Spring (CS). This result demonstrated that the gene 5AQ was the mutated gene of dsc. The expression levels of 5AQ were significantly higher in roots, stems, leaves and spikes of mutant dsc than those in WT. Our results demonstrated that point mutation in the miR172 binding site of the 5AQ likely increased its transcript level via a reduction in miRNA-dependent degradation, and this resulted in pleiotropic effects on spikelet density and plant height. Obviously, miR172-Q was a key regulation module for wheat growth and spike development. The dCAPS marker could be used to detect the elite allele of Q in wheat breeding. Regulation of miR172-Q module might be an approach for wheat yield breeding.

Heterotrimeric G-proteins are multifunctional modulators that participate in a wide range of growth and developmental processes in eukaryotic species, including yeast, plants, and animals. In this study, we characterized a maize mutant, ct2, that showed a compact architecture and reproductive-organ-related phenotypic variation. Heredity analysis indicated that the mutant phenotypes resulted from monogenic inheritance. The target gene, CT2, was cloned using bulked segregant analysis and map-based cloning. Sequence alignment showed that the ct2 mutation was the result of a 185-bp sequence insertion at the 3' terminal of CT2. Protein structure prediction and phylogenetic analysis indicated that CT2 is a canonical Gɑ of monocotyledonous plants. Through phenotypic identification, we found that CT2 was involved in yield-related traits in maize. Furthermore, our findings indicated that CT2 promotes cell proliferation in stem internodes, which may result from the upregulation of zeatin biosynthesis by CT2. This research provides direction for further studies in the biological function of CT2 in cell proliferation and in yield-related traits, which will be beneficial for maize breeding through screening and application of beneficial alleles.

Primary microcephaly (MCPH) is an autosomal recessive condition of reduced head circumference due to a small cerebral cortex. Genetic studies have reported 30 MCPH genes. The aim of this study was to investigate whether the genetic mapping of the MCPH gene mutation is involved in primary microcephaly. For genetic mapping, whole exome and Sanger sequencing were performed. In this study, we identified a homozygous missense mutation, NM_001259.8:c.589G[A, p.(Ala197Thr) of CDK6 in a consanguineous MCPH family. Since the identification of CDK6 as a candidate gene for MCPH, this is the first report of an additional family mapping to the MCPH12locus. Molecular-genetic analysis of both families revealed an overlapping homozygous region harbouring the causal mutation in CDK6 and a common haplotype, which led to a significant reduction of the critical MCPH12 locus. Our results suggest a founder effect of c.589G[A, p.(Ala197Thr) in the Pakistani population.

The stems of Zizania latifolia, an important vegetable in China, are targeted by the pathogen Ustilago esculenta, triggering a response through the mitogen-activated protein kinase (MAPK) signalling pathway. To investigate the characteristics and the role of MAPK gene family in the biological stress response, a bioinformatics-based analysis was performed, and the expression patterns of ZlMPKs and MAPK-infection pathway-related genes were detected in male plants inoculated with U. esculenta. Twenty-five ZlMPK genes were identified and divided into four subgroups A, B, C and D: carried a conserved TEY motif, while D had a conserved TDY motif. The ZlMPKs were located in the nucleus, cytoplasm, chloroplast, mitochondria, and peroxisome, and most exhibited evidence of gene duplication events. The relative expression of most ZlMPKs was the highest at 3 h after inoculation with U. esculenta, with 21 ZlMPKs being upregulated and four being downregulated. Additionally, nine of 11 MAPK-infection pathway-related genes were upregulated at 3 h after inoculation. ZlMPK3 was cloned and transformed into Arabidopsis thaliana, and two overexpression lines were identified by resistance screening and molecular detection. Their responses to Botrytis cinerea infection were studied. The leaf inoculation sites of ZlMPK3-overexpression plants revealed damage, while those of wild-type plants did not. The relative expression of MAPK pathogen related genes was altered after inoculation. Specifically, the expression levels of the ethylene biosynthetic pathway gene AtACS6 and five cysteine-rich secretory protein CAP genes were significantly upregulated, while those of systemic acquired resistance marker gene, pathogenesis-related 1 AtPR1 and early defense signalling gene AtFRK1 were significantly downregulated, indicating that resistance to B. cinerea was weakened in the ZlMPK3-overexpression lines.

The complete mitogenome of the common Chinese whip scorpion, Typopeltis sinensis (Butler, 1872) was sequenced and compared with another Uropygid mitogenome of Mastigoproctus giganteus (Lucas, 1835). Structural divergences include the absence of one tRNA-Leu and strand inversions in four protein coding genes (PCGs). All PCGs showed K_a/K_s ratios-1, which indicates purifying selection, with COI (0.04) evolving the most conservatively and ATP8 (0.65) accumulating the highest nonsynonymous substitutions. Phylogenetic reconstruction based on 602-bp COI sequences from seven species indicates that T. sinensis is most closely related to T. stimpsonii.

This study aimed to understand the maternal influence on the inheritance of pericarp colour and grain dimensions in rice, serving as a model for maternal effects in plants. Four crosses, namely Kalarata (red pericarp) x DRR Dhan 58 (white pericarp), DRR Dhan 58 x Kalarata, Kalarata x Pusa 44 (white pericarp), and Pusa 44 x Kalarata, were attempted and their F₁, F₂ and F₃ seeds were analysed. All F₁ seeds of all crosses exhibited the pericarp colour of their corresponding maternal parent, confirming a strong maternal influence. In subsequent generations, F₂ seeds uniformly exhibited red pericarp colour across all crosses, thus reinforcing the influence of maternal genotype on inheritance. However, F₃ seeds were segregated into 9 red: 3 medium red: 4 white, suggesting digenic recessive epistasis (supplementary gene action). Phenotypic assessments indicated nuclear inheritance with maternal effects, while genotypic analysis using gene-based markers revealed polymorphisms at 'Rc' locus and monomorphism at 'Rd' locus, indicating the presence of specific genetic factors in the parental materials used in the study. Additionally, analysis of the grain L/B ratio revealed a similar trend to pericarp colour inheritance, with direct maternal genetic effects in F₁ seeds, consistent uniformity in F₂ seeds and continuous variation in F₃ seeds across all crosses. Welch's test comparisons of L/B ratios suggested a significant maternal impact, particularly in F₃ and F₂ generations, with paternal influence remaining consistent across generations. Deviations in the L/B ratios in certain F₃ segregants suggest environmental influences on grain development. These findings contribute to the understanding of maternal effects in plants and have important implications for rice breeding. The significance of this research lies in its contribution to the relatively unexplored field of maternal effects in plant genetics.

The sev-Gal4 driver is widely used in Drosophila to express the target gene in specific subsets of cells in ommatidial units of the developing eye. A 2015 report (Ray and Lakhotia, J. Genet. 94, 407-416) from our laboratory claimed that besides the eye disc cells, the sev-Gal4 (Bloomington stock 5793) also expresses in eight pairs of dorsomedial neurons and some other cells in larval and early pupal ventral ganglia. The current study reveals that this claim was incorrect since the UAS-GFP transgene in Bloomington stock 1521 used as a reporter in the 2015 study expresses in the eight pairs of dorsomedial neurons and some other cells in larval and early pupal ventral ganglia even in undriven condition. The UAS-eGFP reporter in the BL-5431 stock, however, does not express in these ganglia, neither in undriven nor in sev-Gal4 driven condition. This was also confirmed by the G-TRACE cell lineage study. Present results suggest that only four dorsalmidline cells in the ventral ganglia and a cluster of cells in the central region of the brain hemisphere, besides the earlier known cells in the eye disc and optic lobe of the brain, express the sev-Gal4 transgene in the stock 5793. The essentiality of examining the undriven expression of a transgene cannot be over-emphasized.

High-altitude ecosystems in the Himalayas exhibit extreme seasonal variations in their vegetation, with summer and winter presenting the most pronounced environmental contrasts. As winter progresses, temperatures drop, and deciduous plant species undergo senescence. This study unravels the transcriptomic dynamics driving leaf senescence in Himalayan treeline species, Betula utilis, during seasonal variations. Using the RNA-sequence technology, leaf samples collected under fresh and senescent stages were analysed to deduce expression profiles at different stages. A total of 6505 differentially expressed transcripts were identified, with functional annotations revealing key senescence pathways such as phytohormonal regulation, chlorophyll degradation, and nutrient remobilisation. The upregulation of senescence-associated genes (SAGs), alongside alterations in transcription factors like WRKY and hormonal pathways, highlights the molecular interplay driving seasonal adaptation. Additionally, chlorophyll catabolism, modulated by NYC1 and PAO, was observed as a pivotal response to winter conditions. The findings of the study provide insights into the importance of carbohydrate metabolism, hormonal signalling, and stress adaptation-related pathways in nutrient conservation and plant fitness under environmental stress. This study offers a comprehensive understanding of the genetic mechanisms that allow B. utilis to withstand the harsh Himalayan climate, adding invaluable information to the fields of plant senescence, stress physiology, and climate resilience.