Sequencing and annotation of the chloroplast DNAs and identification of polymorphisms distinguishing normal male-fertile and male-sterile cytoplasms of onion

Genome ◽  
2013 ◽  
Vol 56 (12) ◽  
pp. 737-742 ◽  
Author(s):  
Christopher von Kohn ◽  
Agnieszka Kiełkowska ◽  
Michael J. Havey

Male-sterile (S) cytoplasm of onion is an alien cytoplasm introgressed into onion in antiquity and is widely used for hybrid seed production. Owing to the biennial generation time of onion, classical crossing takes at least 4 years to classify cytoplasms as S or normal (N) male-fertile. Molecular markers in the organellar DNAs that distinguish N and S cytoplasms are useful to reduce the time required to classify onion cytoplasms. In this research, we completed next-generation sequencing of the chloroplast DNAs of N- and S-cytoplasmic onions; we assembled and annotated the genomes in addition to identifying polymorphisms that distinguish these cytoplasms. The sizes (153 538 and 153 355 base pairs) and GC contents (36.8%) were very similar for the chloroplast DNAs of N and S cytoplasms, respectively, as expected given their close phylogenetic relationship. The size difference was primarily due to small indels in intergenic regions and a deletion in the accD gene of N-cytoplasmic onion. The structures of the onion chloroplast DNAs were similar to those of most land plants with large and small single copy regions separated by inverted repeats. Twenty-eight single nucleotide polymorphisms, two polymorphic restriction-enzyme sites, and one indel distributed across 20 chloroplast genes in the large and small single copy regions were selected and validated using diverse onion populations previously classified as N or S cytoplasmic using restriction fragment length polymorphisms. Although cytoplasmic male sterility is likely associated with the mitochondrial DNA, maternal transmission of the mitochondrial and chloroplast DNAs allows for polymorphisms in either genome to be useful for classifying onion cytoplasms to aid the development of hybrid onion cultivars.

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yan-Yan Guo ◽  
Jia-Xing Yang ◽  
Ming-Zhu Bai ◽  
Guo-Qiang Zhang ◽  
Zhong-Jian Liu

Abstract Background Paphiopedilum is the largest genus of slipper orchids. Previous studies showed that the phylogenetic relationships of this genus are not well resolved, and sparse taxon sampling documented inverted repeat (IR) expansion and small single copy (SSC) contraction of the chloroplast genomes of Paphiopedilum. Results Here, we sequenced, assembled, and annotated 77 plastomes of Paphiopedilum species (size range of 152,130 – 164,092 bp). The phylogeny based on the plastome resolved the relationships of the genus except for the phylogenetic position of two unstable species. We used phylogenetic and comparative genomic approaches to elucidate the plastome evolution of Paphiopedilum. The plastomes of Paphiopedilum have a conserved genome structure and gene content except in the SSC region. The large single copy/inverted repeat (LSC/IR) boundaries are relatively stable, while the boundaries of the inverted repeat and small single copy region (IR/SSC) varied among species. Corresponding to the IR/SSC boundary shifts, the chloroplast genomes of the genus experienced IR expansion and SSC contraction. The IR region incorporated one to six genes of the SSC region. Unexpectedly, great variation in the size, gene order, and gene content of the SSC regions was found, especially in the subg. Parvisepalum. Furthermore, Paphiopedilum provides evidence for the ongoing degradation of the ndh genes in the photoautotrophic plants. The estimated substitution rates of the protein coding genes show accelerated rates of evolution in clpP, psbH, and psbZ. Genes transferred to the IR region due to the boundary shift also have higher substitution rates. Conclusions We found IR expansion and SSC contraction in the chloroplast genomes of Paphiopedilum with dense sampling, and the genus shows variation in the size, gene order, and gene content of the SSC region. This genus provides an ideal system to investigate the dynamics of plastome evolution.


Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 180
Author(s):  
Bagdevi Mishra ◽  
Bartosz Ulaszewski ◽  
Sebastian Ploch ◽  
Jaroslaw Burczyk ◽  
Marco Thines

Chloroplasts are difficult to assemble because of the presence of large inverted repeats. At the same time, correct assemblies are important, as chloroplast loci are frequently used for biogeography and population genetics studies. In an attempt to elucidate the orientation of the single-copy regions and to find suitable loci for chloroplast single nucleotide polymorphism (SNP)-based studies, circular chloroplast sequences for the ultra-centenary reference individual of European Beech (Fagus sylvatica), Bhaga, and an additional Polish individual (named Jamy) was obtained based on hybrid assemblies. The chloroplast genome of Bhaga was 158,458 bp, and that of Jamy was 158,462 bp long. Using long-read mapping on the configuration inferred in this study and the one suggested in a previous study, we found an inverted orientation of the small single-copy region. The chloroplast genome of Bhaga and of the individual from Poland both have only two mismatches as well as three and two indels as compared to the previously published genome, respectively. The low divergence suggests low seed dispersal but high pollen dispersal. However, once chloroplast genomes become available from Pleistocene refugia, where a high degree of variation has been reported, they might prove useful for tracing the migration history of Fagus sylvatica in the Holocene.


Development ◽  
2001 ◽  
Vol 128 (7) ◽  
pp. 1119-1126 ◽  
Author(s):  
T.L. Rankin ◽  
M. O'Brien ◽  
E. Lee ◽  
K. Wigglesworth ◽  
J. Eppig ◽  
...  

All vertebrate eggs are surrounded by an extracellular matrix. This matrix is known as the zona pellucida in mammals and is critically important for the survival of growing oocytes, successful fertilization and the passage of early embryos through the oviduct. The mouse zona pellucida is composed of three glycoproteins (ZP1, ZP2 and ZP3), each encoded by a single copy gene. Using targeted mutagenesis in embryonic stem cells, Zp2-null mouse lines have been established. ZP1 and ZP3 proteins continue to be synthesized and form a thin zona matrix in early follicles that is not sustained in pre-ovulatory follicles. The abnormal zona matrix does not affect initial folliculogenesis, but there is a significant decrease in the number of antral stage follicles in ovaries isolated from mice lacking a zona pellucida. Few eggs are detected in the oviduct after stimulation with gonadotropins, and no two-cell embryos are recovered after mating Zp2-null females with normal male mice. The structural defect is more severe than that observed in Zp1-null mice, which have decreased fecundity, but not quite as severe as that observed in Zp3-null mice, which never form a visible zona pellucida and are sterile. Although zona-free oocytes matured and fertilized in vitro can progress to the blastocyst stage, the developmental potential of blastocysts derived from either Zp2- or Zp3-null eggs appears compromised and, after transfer to foster mothers, live births have not been observed. Thus, in addition to its role in fertilization and protection of early embryos, these data are consistent with the zona pellucida maintaining interactions between granulosa cells and oocytes during folliculogenesis that are critical to maximize developmental competence of oocytes.


2001 ◽  
Vol 58 (2) ◽  
pp. 347-356 ◽  
Author(s):  
M. A. GITZENDANNER ◽  
P. S. SOLTIS

Plant conservation genetics has been hampered by a lack of markers for studies of levels and patterns of variation in rare species. We investigated the levels of variation in several rare and widespread species of the western North American genus Lomatium Raf. (Apiaceae) using two relatively new molecular markers: AFLPs and single-strand conformation polymorphisms (SSCPs). For each species, approximately 150 AFLP loci have been scored, yielding estimates of species-level percent polymorphic loci in rare species ranging from near zero to over 80%. Levels of AFLP diversity were similar in two of the rare species, L. bradshawii (Rose ex Mathias) Mathas & Constance and L. ochocense Helliwell & Constance, and the widespread species. The third rare species, L. cookii Kagan, which has small populations, has low levels of diversity based on AFLPs. We also examined nucleotide diversity at the single-copy nuclear-DNA locus glyceraldehyde 3-phosphate dehydrogenase (Gap-C). PCR-amplified segments were analysed for allelic variation using SSCPs, and intrapopulational nucleotide polymorphisms were identified in both L. bradshawii and L. cookii. In the 211bp segment of Gap-C analysed, five nucleotide sites were segregating within populations of L. bradshawii and two in L. cookii.


2018 ◽  
Author(s):  
Pei-Hsuan Wu ◽  
Yu Fu ◽  
Katharine Cecchini ◽  
Deniz M. Özata ◽  
Amena Arif ◽  
...  

SUMMARYPachytene piRNAs, which comprise >80% of small RNAs in the adult mouse testis, have been proposed to bind and regulate target RNAs like miRNAs, cleave targets like siRNAs, or lack biological function altogether. Although piRNA pathway protein mutants are male sterile, no biological function has been identified for any mammalian piRNA-producing locus. Here, we report that males lacking piRNAs from a conserved mouse pachytene piRNA locus on chromosome 6 (pi6) produce sperm with defects in capacitation and egg fertilization. Moreover, heterozygous embryos sired bypi6−/−fathers show reduced viability in utero. Molecular analyses suggest thatpi6piRNAs repress gene expression by cleaving mRNAs encoding proteins required for sperm function.pi6also participates in a network of piRNA-piRNA precursor interactions that initiate piRNA production from a second piRNA locus on chromosome 10 as well aspi6itself. Our data establish a direct role for pachytene piRNAs in spermiogenesis and embryo viability.HighlightsNormal male mouse fertility and spermiogenesis require piRNAs from thepi6locusSperm capacitation and binding to the zona pellucida of the egg requirepi6piRNAsHeterozygous embryos sired bypi6−/−fathers show reduced viability in uteroDefects inpi6mutant sperm reflect changes in the abundance of specific mRNAs.


2021 ◽  
Vol 46 (1) ◽  
pp. 162-174
Author(s):  
Ming-Hui Yan ◽  
Chun-Yang Li ◽  
Peter W. Fritsch ◽  
Jie Cai ◽  
Heng-Chang Wang

Abstract—The phylogenetic relationships among 11 out of the 12 genera of the angiosperm family Styracaceae have been largely resolved with DNA sequence data based on all protein-coding genes of the plastome. The only genus that has not been phylogenomically investigated in the family with molecular data is the monotypic genus Parastyrax, which is extremely rare in the wild and difficult to collect. To complete the sampling of the genera comprising the Styracaceae, examine the plastome composition of Parastyrax, and further explore the phylogenetic relationships of the entire family, we sequenced the whole plastome of P. lacei and incorporated it into the Styracaceae dataset for phylogenetic analysis. Similar to most others in the family, the plastome is 158189 bp in length and contains a large single-copy region of 88085 bp and a small single-copy region of 18540 bp separated by two inverted-repeat regions of 25781 bp each. A total of 113 genes was predicted, including 79 protein-coding genes, 30 tRNA genes, and four rRNA genes. Phylogenetic relationships among all 12 genera of the family were constructed with 79 protein-coding genes. Consistent with a previous study, Styrax, Huodendron, and a clade of Alniphyllum + Bruinsmia were successively sister to the remainder of the family. Parastyrax was strongly supported as sister to an internal clade comprising seven other genera of the family, whereas Halesia and Pterostyrax were both recovered as polyphyletic, as in prior studies. However, when we employed either the whole plastome or the large- or small-single copy regions as datasets, Pterostyrax was resolved as monophyletic with 100% support, consistent with expectations based on morphology and indicating that non-coding regions of the Styracaceae plastome contain informative phylogenetic signal. Conversely Halesia was still resolved as polyphyletic but with novel strong support.


Development ◽  
1988 ◽  
Vol 104 (1) ◽  
pp. 165-173 ◽  
Author(s):  
C.H. Barton ◽  
G. Dickson ◽  
H.J. Gower ◽  
L.H. Rowett ◽  
W. Putt ◽  
...  

Neural cell adhesion molecules (N-CAMs) are a family of cell surface sialoglycoproteins encoded by a single copy gene. A full-length cDNA clone that encodes a nontransmembrane phosphatidylinositol (PI) linked N-CAM of Mr 125 × 10(3) has been isolated from a human skeletal muscle cDNA library. The deduced protein sequence encodes a polypeptide of 761 amino acids and is highly homologous to the N-CAM isoform in brain of Mr 120 × 10(3). The size difference between the 125 × 10(3). The size difference between the 125 × 10(3) Mr skeletal muscle form and the 120 × 10(3) Mr N-CAM form from brain is accounted for by the insertion of a block of 37 amino acids called MSD1, in the extracellular domain of the muscle form. Transient expression of the human cDNA in COS cells results in cell surface N-CAM expression via a putative covalent attachment to PI-containing phospholipid. Linked in vitro transcription and translation experiments followed by immunoprecipitation with anti-N-CAM antibodies demonstrate that the full-length clone of 761 amino acid coding potential produces a core polypeptide of Mr 110 × 10(3) which is processed by microsomal membranes to yield a 122 × 10(3) Mr species. Taken together, these results demonstrate that the cloned cDNA sequence encodes a lipid-linked, PI-specific phospholipase C releasable surface isoform of N-CAM with core glycopeptide molecular weight corresponding to the authentic muscle 125 × 10(3) Mr N-CAM isoform. This is the first direct correlation of cDNA and deduced protein sequence with a known PI-linked N-CAM isoform from skeletal muscle.


2020 ◽  
Vol 10 (4) ◽  
pp. 1309-1318
Author(s):  
Tzu-Kai Lin ◽  
Ya-Ping Lin ◽  
Shun-Fu Lin

Male sterility has been widely used in hybrid seed production in Brassica, but not in B. rapa ssp. chinensis, and genetic models of male sterility for this subspecies are unclear. We discovered a spontaneous mutant in B. rapa ssp. chinensis. A series of progeny tests indicated that male sterility in B. rapa ssp. chinensis follows a three-allele model with BrMsa, BrMsb, and BrMsc. The male sterility locus has been mapped to chromosome A07 in BC1 and F2 populations through genotyping by sequencing. Fine mapping in a total of 1,590 F2 plants narrowed the male sterility gene BrMs to a 400 kb region, with two SNP markers only 0.3 cM from the gene. Comparative gene mapping shows that the Ms gene in B. rapa ssp. pekinensis is different from the BrMs gene of B. rapa ssp. chinensis, despite that both genes are located on chromosome A07. Interestingly, the DNA sequence orthologous to a male sterile gene in Brassica napus, BnRf, is within 400 kb of the BrMs locus. The BnRf orthologs of B. rapa ssp. chinensis were sequenced, and one KASP marker (BrMs_indel) was developed for genotyping based on a 14 bp indel at intron 4. Cosegregation of male sterility and BrMs_indel genotypes in the F2 population indicated that BnRf from B. napus and BrMs from B. rapa are likely to be orthologs. The BrMs_indel marker developed in this study will be useful in marker-assisted selection for the male sterility trait.


Sign in / Sign up

Export Citation Format

Share Document