Moths and butterflies (Lepidoptera) have sex chromosome systems with female heterogamety, and 2 models, W-dominance and Z-counting, have been proposed to determine sex. The W-dominant mechanism is well known in Bombyx mori. However, little is known about the Z-counting mechanism in Z0/ZZ species. We investigated whether ploidy changes affect sexual development and gene expression in the eri silkmoth, Samia cynthia ricini (2n = 27♀/28♂, Z0♀/ZZ♂). Tetraploid males (4n = 56, ZZZZ) and females (4n = 54, ZZ) were induced by heat and cold shock, and then, triploid embryos were produced by crosses between diploids and tetraploids. Two karyotypes (3n = 42, ZZZ and 3n = 41, ZZ) were identified in triploid embryos. Triploid embryos with 3 Z chromosomes showed male-specific splicing of the S. cynthia doublesex (Scdsx) gene, whereas 2-Z triploid embryos showed both male- and female-specific splicing. From larva to adult, 3-Z triploids showed a normal male phenotype, except for defects in spermatogenesis. However, abnormal gonads were observed in 2-Z triploids, which showed both male- and female-specific Scdsx transcripts not only in the gonads but also in somatic tissues. Two-Z triploids were thus obviously intersexes, suggesting that sexual development in S. c. ricini depends on the Z:A ratio and not only on the Z number. Moreover, mRNA-seq analyses in embryos showed that relative levels of gene expression are similar between samples with different doses of Z chromosomes and autosome sets. Our results provide the first evidence that ploidy changes disrupt sexual development but have no effect on the general mode of dosage compensation in Lepidoptera.
Gene flow between species in the genus Arabidopsis occurs in significant amounts, but how exactly gene flow is achieved is not well understood. Polyploidization may be one avenue to explain gene flow between species. One problem, however, with polyploidization as a satisfying explanation is the occurrence of lethal genomic instabilities in neopolyploids as a result of genomic exchange, erratic meiotic behavior, and genomic shock. We have created an autoallohexaploid by pollinating naturally co-occurring diploid Arabidopsis thaliana with allotetraploid Arabidopsis suecica (an allotetraploid composed of A. thaliana and Arabidopsis arenosa). Its triploid offspring underwent spontaneous genome duplication and was used to generate a multigenerational pedigree. Using genome resequencing, we show that 2 major mechanisms promote stable genomic exchange in this population. Legitimate meiotic recombination and chromosome segregation between the autopolyploid chromosomes of the 2 A. thaliana genomes occur without any obvious bias for the parental origin and combine the A. thaliana haplotypes from the A. thaliana parent with the A. thaliana haplotypes from A. suecica similar to purely autopolyploid plants. In addition, we repeatedly observed that occasional exchanges between regions of the homoeologous chromosomes are tolerated. The combination of these mechanisms may result in gene flow leading to stable introgression in natural populations. Unlike the previously reported resynthesized neoallotetraploid A. suecica, this population of autoallohexaploids contains mostly vigorous, and genetically, cytotypically, and phenotypically variable individuals. We propose that naturally formed autoallohexaploid populations might serve as an intermediate bridge between diploid and polyploid species, which can facilitate gene flow rapidly and efficiently.
Autori prezentujú prípad parciálnej hydatidóznej moly, kde DNA analýza (STR – genotypizácia krátkych tandemových opakovaní) poukázala na triandrickú monogynickú tetraploidnú kompozíciu genómu s gonozómovým komplementom XXXY. Uvedený genetický nález, ktorý je zriedkavý v porovnaní s typickými, diandrickými monogynickými triploidnými parciálnymi molami, klinicko-patologicky koreluje s parciálnou molou. Genetická analýza definitívne potvrdila podozrenie na parciálnu molu. Pre vylúčenie možnosti pôvodu molárnej gravidity ako zadržané produkty koncepcie po predchádzajúcej tehotnosti ukončenej interrupciou, boli porovnané STR profily molárnej gravidity a produktu predcházajúcej koncepcie. Genotypizácia krátkych tandemových opakovaní je užitočná molekulárno-genetická metóda v diferenciálnej diagnostike parciálnej hydatidóznej moly, kde sú klinicko-patologické nálezy často nejednoznačné.
The authors present a case of a partial hydatidiform mole where DNA analysis (STR – short tandem repeat genotyping) showed a triandric monogynic tetraploid genome composition with a XXXY gonosomal complement. This genetic finding clinicopathologically correlates with a partial hydatidiform mole, although it is rare in comparison with the typical, diandric monogynic triploid partial moles. The genetic analysis definitively confirmed the suspected diagnosis of a partial mole. To exclude the possibility that molar pregnancy represented retained products of conception after elective pregnancy termination, STR profiles from molar pregnancy and previous products of conception were compared. Short tandem repeats genotyping is a useful molecular genetic method in the differential diagnosis of partial hydatidiform moles, where clinical-pathological findings are frequently ambiguous.
- MeSH
- Adult MeSH
- Fertilization genetics MeSH
- Genotyping Techniques methods instrumentation MeSH
- Abortion, Induced MeSH
- Humans MeSH
- Hydatidiform Mole * diagnosis genetics physiopathology MeSH
- Tetraploidy * MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Female MeSH
- Publication type
- Case Reports MeSH
Hybridogenesis is a hemiclonal reproductive strategy in diploid and triploid hybrids. Our study model is a frog P. esculentus (diploid RL and triploids RLL and RRL), a natural hybrid between P. lessonae (LL) and P. ridibundus (RR). Hybridogenesis relies on elimination of one genome (L or R) from gonocytes (G) in tadpole gonads during prespermatogenesis, but not from spermatogonial stem cells (SSCs) in adults. Here we provide the first comprehensive study of testis morphology combined with chromosome composition in the full spectrum of spermatogenic cells. Using genomic in situ hybridization (GISH) and FISH we determined genomes in metaphase plates and interphase nuclei in Gs and SSCs. We traced genomic composition of SSCs, spermatocytes and spermatozoa in individual adult males that were crossed with females of the parental species and gave progeny. Degenerating gonocytes (24%-39%) and SSCs (18%-20%) led to partial sterility of juvenile and adult gonads. We conclude that elimination and endoreplication not properly completed during prespermatogenesis may be halted when gonocytes become dormant in juveniles. After resumption of mitotic divisions by SSCs in adults, these 20% of cells with successful genome elimination and endoreplication continue spermatogenesis, while in about 80% spermatogenesis is deficient. Majority of abnormal cells are eliminated by cell death, however some of them give rise to aneuploid spermatocytes and spermatozoa which shows that hybridogenesis is a wasteful process.
- Publication type
- Journal Article MeSH
OBJECTIVES: We tested the toxicity of ethinylestradiol, a semisynthetic estrogen used in oral contraceptives, on all-male triploid zebrafish using commercial feeds and three different doses concentrations. We aimed to determine whether ethinylestradiol peroral administration resulted in vitellogenin production and whether all-male triploid zebrafish could serve as a model species for xenoestrogen testing. METHODS: The actual concentrations of 17α-ethinylestradiol were 0.0035 (low); 0.0315 (medium) and 0.365 (high) μg/g. Positive control represented commercial feeds containing 0.0465 μg/g of β-estradiol. The experiment lasted 8 weeks. RESULTS: Our results indicate that 17α-ethinylestradiol consumption does induce vitellogenin production in triploid zebrafish. CONCLUSIONS: The simple presence of vitellogenin is a definite symptom indicative of the potential for such changes due to the action of estrogenic substances. As such, this experiment has shown that the use of all-male triploid zebrafish populations, rather than the mixed-sex populations of other species previously used, could serve as a suitable alternative model population for controlled testing of the effects of xenoestrogens on fish.
- MeSH
- Water Pollutants, Chemical * MeSH
- Zebrafish * genetics MeSH
- Estrogens pharmacology MeSH
- Ethinyl Estradiol toxicity MeSH
- Triploidy MeSH
- Vitellogenins genetics MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Wild barley is abundant, occupying large diversity of sites, ranging from the northern mesic Mediterranean meadows to the southern xeric deserts in Israel. This is also reflected in its wide phenotypic heterogeneity. We investigated the dynamics of DNA content changes in seed tissues in ten wild barley accessions that originated from an environmental gradient in Israel. The flow cytometric measurements were done from the time shortly after pollination up to the dry seeds. We show variation in mitotic cell cycle and endoreduplication dynamics in both diploid seed tissues (represented by seed maternal tissues and embryo) and in the triploid endosperm. We found that wild barley accessions collected at harsher xeric environmental conditions produce higher proportion of endoreduplicated nuclei in endosperm tissues. Also, a comparison of wild and cultivated barley strains revealed a higher endopolyploidy level in the endosperm of wild barley, that is accompanied by temporal changes in the timing of the major developmental phases. In summary, we present a new direction of research focusing on connecting spatiotemporal patterns of endoreduplication in barley seeds and possibly buffering for stress conditions.
- MeSH
- DNA, Plant genetics MeSH
- Endosperm genetics MeSH
- Genetic Variation genetics MeSH
- Hordeum genetics MeSH
- Polyploidy MeSH
- Genetics, Population methods MeSH
- Seeds genetics MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- Israel MeSH
The large-sized tapeworm Dibothriocephalus latus is known as the broad or fish-borne cestode of mammals that is capable to infect humans and cause diphyllobothriosis. Recently, molecular data on D. latus has been accumulating in the literature and a complete genome sequence has been published; however, little is known about the karyotype and chromosome architecture. In this study, an in-depth karyological analysis of 2 D. latus specimens was carried out. The plerocercoids originated from a perch caught in subalpine Lake Iseo (Italy) and the tapeworms were reared in hamsters. Both specimens contained cells with a highly variable number of chromosomes ranging from18 to 27. Nevertheless, the largest portion of mitotic figures (47%) showed a number corresponding to the triploid set, 3n = 27. Accordingly, the karyotype of the analyzed specimens consisted of 9 triplets of metacentric chromosomes. Fluorescence in situ hybridization (FISH) with the 18S rDNA probe clearly demonstrated the presence of 3 clusters of hybridization signals on the triplet of chromosome 7, thus confirming the triploid status of the specimens. FISH with a telomeric (TTAGGG)n probe confined hybridization signals exclusively to the terminal chromosomal regions, supporting the earlier findings that this repetitive motif is a conserved feature of tapeworm telomeres.
- MeSH
- Chromosomes genetics MeSH
- Cytogenetic Analysis MeSH
- Diphyllobothriasis parasitology MeSH
- Diphyllobothrium genetics metabolism MeSH
- In Situ Hybridization, Fluorescence MeSH
- Karyotype MeSH
- RNA, Helminth analysis MeSH
- RNA, Ribosomal, 18S analysis MeSH
- Triploidy * MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
Cieľ: Cieľom práce bola genetická charakterizácia súboru prípadov suspektných z parciálnej moly hydatidózy na základe nejednoznačného morfologického obrazu placentárneho tkaniva. Súbor a metodika: Práca predkladá výsledky genetickej analýzy súboru 10 pacientok s rôznymi klinickými prejavmi reprodukčných strát, u ktorých bola na základe histopatologického vyšetrenia suponovaná parciálna mola hydatidóza. Kompozícia genómu produktu koncepcie bola určená genotypizáciou krátkych tandemových opakovaní (STR – short tandem repeats) použitím komerčnej súpravy „Devyser Compact v3“ (Devyser). Výsledky a závery: Z 10 vyšetrených prípadov bol v piatich zistený diandrický monogynický triploidný genóm charakteristický pre parciálnu molu. V štyroch prípadoch boli vylúčené aneuploidie chromozómov 13, 18, 21, X a Y, v jednom prípade bol diagnostikovaný Patauov syndróm. Pri nejednoznačnom histopatologickom obraze môže patológom v diferenciálnej diagnostike parciálnej moly významne pomôcť konzultačná DNA analýza (ideálne STR genotypizácia). Histopatologický obraz parciálnej moly hydatidózy môže byť v skorých štádiách gravidity v niektorých prípadoch neúplný a nejednoznačný, čo môže viesť k falošne negatívnemu výsledku vyšetrenia. Na druhej strane, mnohé iné patológie, napr. aneuploidie alebo digynická triploidia, môžu mať histopatologický obraz podobný parciálnej mole, čo naopak vedie k falošnej pozitivite vyšetrenia. Presná diagnostika parciálnej moly hydatidózy použitím molekulárnych genetických metód prispeje k stanoveniu adekvátnej dispenzárnej starostlivosti.
Objective: The aim of the study was the genetic characterization of a set of cases with an unclear morphological profile of the placental tissue suspected of a partial hydatidiform mole. Patients and methods: This work presents the results of a genetic analysis of a group of 10 patients with various clinical manifestations of reproductive loss, where a partial hydatidiform mole was suspected on the basis of a histopathological examination. The composition of the genome of the products of conception was determined by short tandem repeats (STR) genotyping using a commercial kit “Devyser Compact v3 (Devyser) “. Results and conclusions: Out of 10 analyzed cases, five had diandric monogynic triploid genome, characteristic for a partial mole. Aneuploidies of chromosomes 13, 18, 21, X and Y were excluded in four cases and Patau‘s syndrome was diagnosed in one case. In the case of an unclear histopathological profile, consultative DNA analysis (ideally STR genotyping) can significantly help the pathologist in the differential diagnosis of a partial mole. The histopathological profile of a partial hydatidiform mole may be in some cases incomplete and unclear, especially in the early weeks of gestation, which can lead to false negativity of the examination. On the other hand, other pathologies, for example aneuploides or digynic triploidy, may produce a histopathological profile similar to a partial mole, which leads to false positivity. Accurate diagnosis of a partial hydatidiform mole using molecular genetic methods contributes to the determination of adequate dispensary care for patients.
In pathogenic fungi and oomycetes, interspecific hybridization may lead to the formation of new species having a greater impact on natural ecosystems than the parental species. From the early 1990s, a severe alder (Alnus spp.) decline due to an unknown Phytophthora species was observed in several European countries. Genetic analyses revealed that the disease was caused by the triploid hybrid P. × alni, which originated in Europe from the hybridization of P. uniformis and P. × multiformis. Here, we investigated the population structure of P. × alni (158 isolates) and P. uniformis (85 isolates) in several European countries using microsatellite markers. Our analyses confirmed the genetic structure previously observed in other European populations, with P. uniformis populations consisting of at most two multilocus genotypes (MLGs) and P. × alni populations dominated by MLG Pxa-1. The genetic structure of P. × alni populations in the Czech Republic, Hungary and Sweden seemed to reflect the physical isolation of river systems. Most rare P. × alni MLGs showed a loss of heterozygosity (LOH) at one or a few microsatellite loci compared with other MLGs. This LOH may allow a stabilization within the P. × alni genome or a rapid adaptation to stress situations. Alternatively, alleles may be lost because of random genetic drift in small, isolated populations, with no effect on fitness of P. × alni. Additional studies would be necessary to confirm these patterns of population diversification and to better understand the factors driving it.
- MeSH
- Ecosystem MeSH
- Genetic Variation MeSH
- Genotype MeSH
- Microsatellite Repeats genetics MeSH
- Plant Diseases MeSH
- Phytophthora * genetics MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Europe MeSH
- Sweden MeSH
Understanding the mechanisms regulating the development of cereal seeds is essential for plant breeding and increasing yield. However, the analysis of cereal seeds is challenging owing to the minute size, the liquid character of some tissues, and the tight inter-tissue connections. Here, we demonstrate a detailed protocol for dissection of the embryo, endosperm, and seed maternal tissues at early, middle, and late stages of barley seed development. The protocol is based on a manual tissue dissection using fine-pointed tools and a binocular microscope, followed by ploidy analysis-based purity control. Seed maternal tissues and embryos are diploid, while the endosperm is triploid tissue. This allows the monitoring of sample purity using flow cytometry. Additional measurements revealed the high quality of RNA isolated from such samples and their usability for high-sensitivity analysis. In conclusion, this protocol describes how to practically dissect pure tissues from developing grains of cultivated barley and potentially also other cereals.
