scholarly journals Gametogenesis of intergroup hybrids of hemiclonal frogs

2007 ◽  
Vol 89 (1) ◽  
pp. 39-45 ◽  
Author(s):  
MATILDE RAGGHIANTI ◽  
STEFANIA BUCCI ◽  
SILVIA MARRACCI ◽  
CLAUDIO CASOLA ◽  
GIORGIO MANCINO ◽  
...  
Keyword(s):  
Germ Line ◽  
Parental Species ◽  
Rana Esculenta ◽  
Population System ◽  
F1 Hybrid ◽  
Water Frog ◽  
System Type ◽  
Genome Exclusion ◽  
European Water Frog

European water frog hybrids Rana esculenta (R. ridibunda×R. lessonae) reproduce hemiclonally, by hybridogenesis: in the germ line they exclude the genome of one parental species and produce haploid gametes with an unrecombined genome of the other parental species. In the widespread L-E population system, both sexes of hybrids (E) coexist with R. lessonae (L). They exclude the lessonae genome and produce ridibunda gametes. In the R-E system, hybrid males coexist with R. ridibunda (R); they exclude either their ridibunda or their lessonae genome and produce sperm with a lessonae or with a ridibunda genome or a mixture of both kinds of sperm. We examined 13 male offspring, 12 of which were from crosses between L-E system and R-E system frogs. All were somatically hybrid. With one exception, they excluded the lessonae genome in the germ line and subsequently endoreduplicated the ridibunda genome. Spermatogonial metaphases contained a haploid or a diploid number of ridibunda chromosomes, identified through in situ hybridization to a satellite DNA marker, and by spermatocyte I metaphases containing a haploid number of ridibunda bivalents. The exception, an F1 hybrid between L-E system R. lessonae and R-E system R. ridibunda, was not hybridogenetic, showed no genome exclusion, and evidenced a disturbed gametogenesis resulting from the combination of two heterospecific genomes. None of the hybridogenetic hybrids showed any cell lines excluding the ridibunda genome, the pattern most frequent in hybrids of the R-E system, unique to that system, and essential for its persistence. A particular combination of R-E system lessonae and R-E system ridibunda genomes seems necessary to induce the R-E system type of hemiclonal gametogenesis.

Development of testes and differentiation of germ cells in water frogs of the Rana esculenta - complex (Amphibia, Anura)

1999 ◽  
Vol 20 (3) ◽  
pp. 251-263 ◽  
Author(s):  
Jolanta Bartmańska ◽  
Maria Ogielska
Keyword(s):  
Germ Cells ◽  
Parental Species ◽  
Sex Differentiation ◽  
Gonad Development ◽  
Rana Esculenta ◽  
Water Frog ◽  
New Class ◽  
Water Frogs ◽  
Rana Esculenta Complex ◽  
European Water Frog

AbstractThe European water frog, Rana esculenta, is a hybrid whose genome is composed of haploid chromosome sets of its parental species R. lessonae and R. ridibunda. Prior to meiosis one of the parental sets is discarded and the other is duplicated (hybridogenesis). In the parental species sex differentiation begins at tadpole stages 28-30 (Gosner, 1960), at stages 30-36 the testes are composed of proliferating pale spermatogonia 1°. At stages 36-39 a new class of spermatogonia I° (dark) appears. Before first hibernation, seminiferous lobules are filled with cysts containing germ cells at various stages of spermatogenesis up to elongating spermatids. In R. esculenta gonad development is affected from the earliest stages: the gonads are smaller and composed of reduced number of spermatogonia I°. The phase of pale spermatogonia I° proliferation is prolonged up to the second year of life. The structure of the gonads, as well as that of germ cells themselves, are often abnormal.

Age structure, size and growth rate of water frogs from central European natural Pelophylax ridibundus-Pelophylax esculentus mixed populations estimated by skeletochronology

2010 ◽  
Vol 31 (2) ◽  
pp. 239-250 ◽  
Author(s):  
Małgorzata Socha ◽  
Maria Ogielska
Keyword(s):  
Parental Species ◽  
Rana Esculenta ◽  
Breeding Sites ◽  
Central European ◽  
Water Frog ◽  
Water Frogs ◽  
Pelophylax Esculentus ◽  
Mixed Populations ◽  
The Difference ◽  
European Water Frog

AbstractCentral European water frog Pelophylax esculentus (formerly known as Rana esculenta) is a natural hybrid between P. lessonae and P. ridibundus. The hybrids reproduce by hybridogenesis and usually share populations with one of the parental species. Natural ridibundus-esculentus (R-E) mixed populations are rare. The population described herein is composed of 80% P. ridibundus and 20% P. esculentus represented by both sexes. We analyzed 159 adults and 228 juveniles. Age of adults collected from breeding sites ranged from 2 to 6 years in males and from 3 to 7 years in females of both taxa. The percentage of individuals older than 5 years was low. Average age of P. ridibundus was higher than that of P. esculentus. In P. ridibundus the average age of females was higher than that of males. In P. esculentus the difference between ages of females and males was not significant. Measurements of yearly radial growth of long bones revealed that the frogs grew intensively before reaching sexual maturity (3 years for females and 2 years for males). In the group of juveniles before I hibernation, P. esculentus were significantly bigger than P. ridibundus, however, there was no difference in body size between both taxa after I hibernation i.e., before the start of a new growth season. Mean LAG-1 diameters were significantly greater in adults P. ridibundus than in juveniles after I hibernation, but not in P. esculentus.

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

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.

scholarly journals Endoparasitic helminths of water frog complex in Poland: do differences exist between the parental species Pelophylax ridibundus and Pelophylax lessonae, and their natural hybrid Pelophylax esculentus?

2011 ◽  
Vol 48 (2) ◽  
pp. 108-115 ◽  
Author(s):  
M. Popiołek ◽  
B. Rozenblut-Kościsty ◽  
M. Kot ◽  
W. Nosal ◽  
M. Ogielska
Keyword(s):  
20Th Century ◽  
Parental Species ◽  
Helminth Species ◽  
Natural Hybrid ◽  
Intensity Of Infection ◽  
Water Frog ◽  
Pelophylax Ridibundus ◽  
Water Frogs ◽  
Pelophylax Esculentus ◽  
Cosmocerca Ornata

AbstractParasitic fauna of water frogs was mainly studied in the second half of the 20th century. However, these studies were done without differentiation into species and hybrids and pooled the 3 taxa as “water frogs” or “green frogs”. The aim of this study was to make an inventory of helminth species as well as their prevalence and intensity of infection in the two parental species (Pelophylax ridibundus and P. lessonae) and the hybrid (P. esculentus) of water frogs from 3 big populations composed of hundreds or thousands of individuals inhabited natural and seminatural landscapes in Poland. Eight helminth species were found: Polystoma integerrimum, Diplodiscus subclavatus, Opisthoglyphe ranae, Gorgodera cygnoides, Haematoloechus variegatus, Oswaldocruzia filiformis, Cosmocerca ornata and Acanthocephalus ranae. The results were compared with data from other, polish and European studies. Additionally we compared the level of infection among water frog taxa.

A new sex dimorphism in the Harderian gland of the frog Rana esculenta

2007 ◽  
Vol 85 (8) ◽  
pp. 909-915 ◽  
Author(s):  
Ismene Serino ◽  
Gaia Izzo ◽  
Diana Ferrara ◽  
Michela d’Istria ◽  
Sergio Minucci
Keyword(s):  
Sexual Dimorphism ◽  
Secretory Activity ◽  
Harderian Gland ◽  
Polymerase Chain Reaction Analysis ◽  
Rana Esculenta ◽  
Rt Pcr ◽  
Polymerase Chain ◽  
Two Peaks ◽  
Constant Expression

The Harderian gland (Hg), the only gland found in the orbit of the frog Rana esculenta L., 1758, probably plays a role in orbital lubrication. The secretory activity of the Hg is seasonal, showing the highest activity in summer. There is little information on Hg gene expression; previously, we identified a mRNA named harderin, whose deduced protein has no homology with other proteins. Differential expression of the harderin transcript between the sexes expressed during the annual cycle implies sexual dimorphism. RT–PCR (reverse transcription – polymerase chain reaction) analysis, revealed that harderin is expressed during the entire year in the Hg of both sexes. It shows a higher level of expression in the female glands than that of male glands. Two peaks of expression, in February and in June, were observed in the female glands, while only the February peak was observed in those of males. These observations were supported by in situ hybridization. Experiments involving gonadectomy and (or) hormonal replacement therapy showed a significant decrease in harderin in the Hg of females; this effect is prevented by estradiol (testosterone had no effect), while ICI (antiestrogen) counteracts the hormonal prevention, suggesting that this sexual dimorphism is under estradiol control. The constant expression of harderin mRNA during the year suggests a probable constitutive role for this molecule.

Genome elimination in diploid and triploid Rana esculenta males: cytological evidence from DNA flow cytometry

Genome ◽  
1990 ◽  
Vol 33 (5) ◽  
pp. 619-627 ◽  
Author(s):  
A. E. Vinogradov ◽  
L. J. Borkin ◽  
R. Günther ◽  
J. M. Rosanov
Keyword(s):  
Flow Cytometry ◽  
Genetic Material ◽  
Rana Esculenta ◽  
Mendelian Inheritance ◽  
Study Data ◽  
Dna Flow Cytometry ◽  
Cytological Evidence ◽  
Water Frog ◽  
A Genome ◽  
Rana Lessonae

Cytological aspects of hemiclonal (meroclonal) inheritance in diploid and triploid males of the hybridogenetic frog Rana esculenta (Rana ridibunda × Rana lessonae) have been studied by DNA flow cytometry. The fact that the R. ridibunda genome contains 16% more DNA than the R. lessonae genome provides the ability to discern cells containing genomes of any species from the water-frog complex under study. Data are presented showing that elimination of the R. ridibunda genome occurs in hybridogenetic males from certain populations. In triploid males, the cytogenetic mechanism of hemiclonal inheritance is simpler than in diploids: after the elimination of a genome (always the genome in the minority in the triploid set; "homogenizing elimination"), no compensatory duplication of the remaining genetic material is necessary, as it is in diploids. The process of elimination can be visualized in triploid males by using DNA flow cytometry to identify cells in the special phase of the spermatogonial cell cycle that we termed the E phase.Key words: Rana esculenta, genome elimination, non-Mendelian inheritance, spermatogenesis, DNA flow cytometry.

Developmental expression of c-kit, a proto-oncogene encoded by the W locus

Development ◽  
1990 ◽  
Vol 109 (4) ◽  
pp. 911-923 ◽  
Author(s):  
A. Orr-Urtreger ◽  
A. Avivi ◽  
Y. Zimmer ◽  
D. Givol ◽  
Y. Yarden ◽  
...  
Keyword(s):  
Germ Cells ◽  
Receptor Tyrosine Kinase ◽  
Germ Line ◽  
Primordial Germ Cells ◽  
Mouse Embryos ◽  
Developmental Expression ◽  
Male Germ Line ◽  
Polypeptide Growth Factors ◽  
Adult Ovary

Developmental expression of the c-kit proto-oncogene, a receptor tyrosine kinase encoded by the W locus, was investigated by in situ hybridization in normal mouse embryos. Early after implantation transcripts were detectable only in the maternal placenta (6 1/2-7 1/2 days p.c.). Subsequently (8 1/2 days p.c.) numerous ectodermal (neural tube, sensory placodes) and endodermal (embryonic gut) derivatives expressed c-kit. Later transcripts were detected also in the blood islands of the yolk sac and in the embryonic liver, the main sites of embryonic hemopoiesis. Around midgestation, transcripts accumulated in the branchial pouches and also in primordial germ cells of the genital ridges. This complex pattern of expression remained characteristic also later in gestation, when c-kit was expressed in highly differentiated structures of the craniofacial area, in presumptive melanoblasts and in the CNS. In the adult ovary, maternal c-kit transcripts were detected. They were present in the oocytes of both immature and mature ovarian follicles, but not in the male germ line, where c-kit expression may be down regulated. Thus, c-kit activity is complex and appears in multiple tissues including those that also display defects in mutations at the W locus where c-kit is encoded. Correlation between W phenotypes and c-kit expression, as well as the regulation of the complex and multiple expression of polypeptide growth factors and receptors, is discussed.

Anandamide regulates the expression of GnRH1, GnRH2, and GnRH-Rs in frog testis

2012 ◽  
Vol 303 (4) ◽  
pp. E475-E487 ◽  
Author(s):  
Rosanna Chianese ◽  
Vincenza Ciaramella ◽  
Donatella Scarpa ◽  
Silvia Fasano ◽  
Riccardo Pierantoni ◽  
...  
Keyword(s):  
Cannabinoid Receptor ◽  
Rana Esculenta ◽  
Sexual Cycle ◽  
Human Testis ◽  
Biosynthetic Enzyme ◽  
Endogenous Production ◽  
Cb1 Antagonist ◽  
Type 1 Cannabinoid Receptor

Gonadotropin-releasing hormone (either GnRH1 or GnRH2) exerts a local activity in vertebrate testis, including human testis. Relationships between endocannabinoid (eCB) and GnRH systems in gonads have never been elucidated in any species so far. To reveal a cross-talk between eCBs and GnRH at testicular level, we characterized the expression of GnRH ( GnRH1 and GnRH2) as well as GnRH receptor ( GnRH-R1, -R2, and -R3) mRNA in the testis of the anuran amphibian Rana esculenta during the annual sexual cycle; furthermore, the corresponding transcripts were localized inside the testis by in situ hybridization. The possible endogenous production of the eCB, anandamide (AEA), was investigated in testis by analyzing the expression of its biosynthetic enzyme, Nape-pld. Incubations of testis pieces with AEA were carried out in the postreproductive period (June) and in February, when a new spermatogenetic wave takes place. In June, AEA treatment significantly decreased GnRH1 and GnRH-R2 mRNA, stimulated the transcription of GnRH2 and GnRH-R1, and did not affect GnRH-R3 expression. In February, AEA treatment upregulated GnRH2 and GnRH-R3 mRNA, downregulated GnRH-R2, and did not affect GnRH1 and GnRH-R1 expression. These effects were mediated by type 1 cannabinoid receptor ( CB1) since they were fully counteracted by SR141716A (Rimonabant), a selective CB1 antagonist. In conclusion, eCB system modulates GnRH activity in frog testis during the annual sexual cycle in a stage-dependent fashion.

scholarly journals Germ line-specific DNA sequences are present on all five micronuclear chromosomes in Tetrahymena thermophila.

1983 ◽  
Vol 3 (11) ◽  
pp. 1909-1919 ◽  
Author(s):  
K M Karrer
Keyword(s):  
In Situ Hybridization ◽  
Dna Sequences ◽  
Tetrahymena Thermophila ◽  
Germ Line ◽  
Plasmid Vector ◽  
Ciliated Protozoan ◽  
Specific Sequence ◽  
Individual Probe ◽  
Vector Pbr322

The development of the macronucleus from the zygotic micronucleus in the ciliated protozoan Tetrahymena spp. involves the elimination of specific DNA sequences (M. C. Yao and M. Gorovsky, Chromosoma 48:1-18 1974). The present study demonstrates that micronucleus-specific DNA is present on all five of the micronuclear chromosomes. Fragments of micronuclear DNA from Tetrahymena thermophila were cloned in the plasmid vector pBR322. A procedure was developed to examine the organization of the cloned sequences in micro- and macronuclear DNA without nick translating each individual probe. Twenty-three percent of randomly selected DNA sequences examined by this method were micronucleus (germ line) specific. They were all members of families of repeated sequences. Hybridization of six micronucleus-specific DNA sequences to micronuclear DNA from nullisomic strains of T. thermophila, which are lacking one or more pairs of chromosomes in the micronucleus, suggested that these sequences are present on several chromosomes. One micronucleus-specific sequence was shown by in situ hybridization to be present on all five of the micronuclear chromosomes.

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