Cytogenetical studies on Triticum dicoccum×Secale Vavilovii F1 hybrid

Abstract Strong deviation of allele frequencies from Mendelian inheritance favoring Mus spretus-derived alleles has been described previously for X-linked loci in four mouse interspecific crosses. We reanalyzed data for three of these crosses focusing on the location of the gene(s) controlling deviation on the X chromosome and the genetic basis for incomplete deviation. At least two loci control deviation on the X chromosome, one near Xist (the candidate gene controlling X inactivation) and the other more centromerically located. In all three crosses, strong epistasis was found between loci near Xist and marker loci on the central portion of chromosome 2. The mechanism for this deviation from Mendelian expectations is not yet known but it is probably based on lethality of embryos carrying particular combinations of alleles rather than true segregation distortion during oogenesis in F1 hybrid females.

Download Full-text

Transcriptomic Analysis of Short-Term Salt-Stress Response in Mega Hybrid Rice Seedlings

Agronomy ◽

10.3390/agronomy11071328 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1328

Author(s):

Noushin Jahan ◽

Yang Lv ◽

Mengqiu Song ◽

Yu Zhang ◽

Liangguang Shang ◽

...

Keyword(s):

Salt Stress ◽

Molecular Mechanisms ◽

Oryza Sativa L ◽

Transcriptome Profiling ◽

Bhlh Transcription Factor ◽

F1 Hybrid ◽

Salt Stress Response ◽

Productivity Losses ◽

Expression Of Genes ◽

Trait Locus

Salinity is a major abiotic stressor that leads to productivity losses in rice (Oryza sativa L.). In this study, transcriptome profiling and heterosis-related genes were analyzed by ribonucleic acid sequencing (RNA-Seq) in seedlings of a mega rice hybrid, Liang-You-Pei-Jiu (LYP9), and its two parents 93–11 and Pei-ai64s (PA64s), under control and two different salinity levels, where we found 8292, 8037, and 631 salt-induced differentially expressed genes (DEGs), respectively. Heterosis-related DEGs were obtained higher after 14 days of salt treatment than after 7 days. There were 631 and 4237 salt-induced DEGs related to heterosis under 7-day and 14-day salt stresses, respectively. Gene functional classification showed the expression of genes involved in photosynthesis activity after 7-day stress treatment, and in metabolic and catabolic activity after 14 days. In addition, we correlated the concurrence of an expression of DEGs for the bHLH transcription factor and a shoot length/salinity-related quantitative trait locus qSL7 that we fine-mapped previously, providing a confirmed case of heterosis-related genes. This experiment reveals the transcriptomic divergence of the rice F1 hybrid and its parental lines under control and salt stress state, and enlightens about the significant molecular mechanisms developed over time in response to salt stress.

Download Full-text

Genetic regulation of coumarin hydroxylase activity in mice. Biochemical characterization of the enzyme from two inbred strains and their F1 hybrid.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(18)50462-2 ◽

1979 ◽

Vol 254 (13) ◽

pp. 5641-5646 ◽

Cited By ~ 1

Author(s):

A W Wood

Keyword(s):

Biochemical Characterization ◽

Genetic Regulation ◽

Inbred Strains ◽

Hydroxylase Activity ◽

F1 Hybrid

Download Full-text

Chromosomal Map of the Model LegumeLotus japonicus

Genetics ◽

10.1093/genetics/161.4.1661 ◽

2002 ◽

Vol 161 (4) ◽

pp. 1661-1672 ◽

Cited By ~ 7

Author(s):

Andrea Pedrosa ◽

Niels Sandal ◽

Jens Stougaard ◽

Dieter Schweizer ◽

Andreas Bachmair

Keyword(s):

Repetitive Sequences ◽

Lotus Japonicus ◽

Chromosome Complement ◽

Linkage Groups ◽

Closely Related Species ◽

F1 Hybrid ◽

Bac Clones ◽

Genomic Regions ◽

Chromosomal Map

AbstractLotus japonicus is a model plant for the legume family. To facilitate map-based cloning approaches and genome analysis, we performed an extensive characterization of the chromosome complement of the species. A detailed karyotype of L. japonicus Gifu was built and plasmid and BAC clones, corresponding to genetically mapped markers (see the accompanying article by Sandal et al. 2002, this issue), were used for FISH to correlate genetic and chromosomal maps. Hybridization of DNA clones from 32 different genomic regions enabled the assignment of linkage groups to chromosomes, the comparison between genetic and physical distances throughout the genome, and the partial characterization of different repetitive sequences, including telomeric and centromeric repeats. Additional analysis of L. filicaulis and its F1 hybrid with L. japonicus demonstrated the occurrence of inversions between these closely related species, suggesting that these chromosome rearrangements are early events in speciation of this group.

Download Full-text

Sequencing an F1 hybrid of Silurus asotus and S. meridionalis enabled the assembly of high-quality parental genomes

Scientific Reports ◽

10.1038/s41598-021-93257-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Weitao Chen ◽

Ming Zou ◽

Yuefei Li ◽

Shuli Zhu ◽

Xinhui Li ◽

...

Keyword(s):

De Novo ◽

Parental Species ◽

F1 Hybrids ◽

Pelteobagrus Fulvidraco ◽

F1 Hybrid ◽

Short Reads ◽

Final Assembly ◽

Genome Complexity ◽

Hybrid Genome ◽

Silurus Asotus

AbstractGenome complexity such as heterozygosity may heavily influence its de novo assembly. Sequencing somatic cells of the F1 hybrids harboring two sets of genetic materials from both of the paternal and maternal species may avoid alleles discrimination during assembly. However, the feasibility of this strategy needs further assessments. We sequenced and assembled the genome of an F1 hybrid between Silurus asotus and S. meridionalis using the SequelII platform and Hi-C scaffolding technologies. More than 300 Gb raw data were generated, and the final assembly obtained 2344 scaffolds composed of 3017 contigs. The N50 length of scaffolds and contigs was 28.55 Mb and 7.49 Mb, respectively. Based on the mapping results of short reads generated for the paternal and maternal species, each of the 29 chromosomes originating from S. asotus and S. meridionalis was recognized. We recovered nearly 94% and 96% of the total length of S. asotus and S. meridionalis. BUSCO assessments and mapping analyses suggested that both genomes had high completeness and accuracy. Further analyses demonstrated the high collinearity between S. asotus, S. meridionalis, and the related Pelteobagrus fulvidraco. Comparison of the two genomes with that assembled only using the short reads from non-hybrid parental species detected a small portion of sequences that may be incorrectly assigned to the different species. We supposed that at least part of these situations may have resulted from mitotic recombination. The strategy of sequencing the F1 hybrid genome can recover the vast majority of the parental genomes and may improve the assembly of complex genomes.

Download Full-text

Global phylogeography of a pantropical mangrove genus Rhizophora

Scientific Reports ◽

10.1038/s41598-021-85844-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Koji Takayama ◽

Yoichi Tateishi ◽

Tadashi Kajita

Keyword(s):

Phylogenetic Trees ◽

Nuclear Dna ◽

Divergence Time ◽

Long Distance ◽

F1 Hybrid ◽

The Pacific ◽

Comprehensive Picture ◽

Dated Phylogeny ◽

Stochastic Mapping ◽

Historical Scenario

AbstractRhizophora is a key genus for revealing the formation process of the pantropical distribution of mangroves. In this study, in order to fully understand the historical scenario of Rhizophora that achieved pantropical distribution, we conducted phylogeographic analyses based on nucleotide sequences of chloroplast and nuclear DNA as well as microsatellites for samples collected worldwide. Phylogenetic trees suggested the monophyly of each AEP and IWP lineages respectively except for R. samoensis and R. × selala. The divergence time between the two lineages was 10.6 million years ago on a dated phylogeny, and biogeographic stochastic mapping analyses supported these lineages separated following a vicariant event. These data suggested that the closure of the Tethys Seaway and the reduction in mangrove distribution followed by Mid-Miocene cooling were key factors that caused the linage diversification. Phylogeographic analyses also suggested the formation of the distinctive genetic structure at the AEP region across the American continents around Pliocene. Furthermore, long-distance trans-pacific dispersal occurred from the Pacific coast of American continents to the South Pacific and formed F1 hybrid, resulting in gene exchange between the IWP and AEP lineages after 11 million years of isolation. Considering the phylogeny and phylogeography with divergence time, a comprehensive picture of the historical scenario behind the pantropical distribution of Rhizophora is updated.

Download Full-text