scholarly journals Single-Locus Inheritance in the Tetraploid Treefrog Hyla versicolor With an Analysis of Expected Progeny Ratios in Tetraploid Organisms

Genetics ◽  
1987 ◽  
Vol 116 (2) ◽  
pp. 299-311
Author(s):  
J Ellen Marsden ◽  
Steven J Schwager ◽  
Bernie May
Keyword(s):  
Null Allele ◽  
Hyla Versicolor ◽  
Crossing Over ◽  
Tetraploid Species ◽  
Double Reduction ◽  
Adequate Knowledge ◽  
Disomic Inheritance ◽  
Segregation Ratios ◽  
Minimum Number ◽  
Species Being

ABSTRACT The recently evolved autotetraploid frog, Hyla versicolor, was examined electrophoretically for evidence of genomic restructuring leading to diploidization. Loci were tested against the progeny ratios expected if inheritance was disomic vs. tetrasomic. Two loci (Mpi and Sod-2) appeared to be inherited tetrasomically, one (Mdh-2) appeared to be inherited disomically, and one (Tpi) appeared to be inherited disomically in one family and tetrasomically in another family, when tested conventionally against 1:2:1 and 1:4:1 segregation ratios. The minimum number of progeny required for this type of analysis for codominant alleles is shown to be 92. Progeny resulting from double reduction were observed, and the occurrence of a null allele class at Mpi was noted. A reexamination of expected progeny ratios in tetraploid organisms reveals that tetrasomic inheritance patterns cannot be predicted without adequate knowledge of the amount of crossing-over, the proportion of tetravalents vs. random bivalents that are formed, and the ratio and types of centromere segregation (alternate and adjacent) that occur from tetravalents in the species being studied. However, disomic inheritance can be unambiguously confirmed only by the production of all heteroallelic gametes from homobivalent, symmetrically heterozygous individuals. In addition, a method is described for estimating genecentromere distances using the ratio of progeny genotypes in certain crosses in tetraploid species.

Inheritance of microsatellite loci in the polyploid lake sturgeon (Acipenser fulvescens)

Genome ◽  
2001 ◽  
Vol 44 (2) ◽  
pp. 185-191 ◽  
Author(s):  
Jonathan D Pyatskowit ◽  
Charles C Krueger ◽  
Harold L Kincaid ◽  
Bernie May
Keyword(s):  
Null Allele ◽  
Female Parent ◽  
Meiotic Drive ◽  
Unreduced Gametes ◽  
Lake Sturgeon ◽  
Acipenser Fulvescens ◽  
Double Reduction ◽  
Disomic Inheritance ◽  
Random Segregation ◽  
Progeny Genotype

Inheritance in the expression of amplicons for four microsatellite primer pairs was determined using 10 families created from gametes of wild lake sturgeon (Acipenser fulvescens). Loci Afu34 and Afu68 expressed a maximum of two even-intensity bands per individual and had progeny genotype ratios that fit disomic inheritance (P > 0.05). Some variation exhibited at Afu34 and Afu68 was attributable to a null allele. Genotype expression at both loci also indicated that one female parent had transmitted unreduced gametes. Primer Afu39 amplified products that exhibited four gene doses, where genotype counts fit expected ratios for disomic inheritance (P > 0.05) indicating amplification of products from two disomic loci that share alleles. Meiotic drive was evident at the Afu39 loci based on a test for random segregation (P < 0.05). Only the expression of Afu19 gave evidence of tetrasomic inheritance based on a single progeny potentially produced by a double reduction gamete. No evidence for proposed octoploid inheritance was observed.Key words: diploid, tetraploid, octoploid, meiotic drive.

scholarly journals FURTHER EVIDENCE FOR A POLYMORPHISM IN GAMETIC SEGREGATION IN THE TETRAPLOID TREEFROG HYLA VERSICOLOR USING A GLUTAMATE OXALOACETIC TRANSAMINASE LOCUS

Genetics ◽  
1983 ◽  
Vol 103 (4) ◽  
pp. 753-769
Author(s):  
Roy G Danzmann ◽  
James P Bogart
Keyword(s):  
Chromosome Segregation ◽  
Null Allele ◽  
Interspecific Cross ◽  
Staining Intensity ◽  
Interspecific Crosses ◽  
Hyla Versicolor ◽  
Hyla Chrysoscelis ◽  
Segregation Ratios ◽  
Aberrant Segregation ◽  
Glutamate Oxaloacetic Transaminase

ABSTRACT Intra- and interspecific cross combinations between the tetraploid treefrog Hyla versicolor, and between H. versicolor and the diploid treefrog Hyla chrysoscelis were performed. Progeny phenotypes resulting from these crosses were examined electrophoretically using a polymorphic glutamate oxaloacetic transminase (GOT-1) locus, to determine the mechanism of chromosome segregation in H. versicolor, and to test theoretical expectations for isozyme expression in interspecific (2n × 4n or 4n × 2n) hybrids. In some intraspecific tetraploid crosses progeny phenotypes fit a disomic mode of segregation, whereas in other crosses a tetrasomic mode of segregation was the most probable. Additional crosses produced phenotypic ratios that conformed to either a disomic or tetrasomic mode of segregation. These results suggest that a polymorphism, with respect to segregation of gametes, exists in H. versicolor, resulting from differences in chromosome pairings during meiosis I. This polymorphism in gametic segregation occurred in both sexes. Certain crosses, however, produced phenotypic ratios that did not conform to any chromosome segregation model. Progeny phenotypes observed from most interspecific crosses conformed to expected interspecific isozyme staining intensity models. Symmetrical heterozygotes, representing either a single dose for both alternate alleles or double doses for both alternate alleles, were also observed. Such phenotypes are unexpected in triploid progeny. A null allele was postulated to account for the aberrant segregation ratios and phenotypes observed in certain intra- and interspecific crosses.

scholarly journals The effect of suppressing crossing-over on the response to selection in Drosophila melanogaster

1970 ◽  
Vol 16 (1) ◽  
pp. 1-16 ◽  
Author(s):  
C. P. McPhee ◽  
Alan Robertson
Keyword(s):  
Drosophila Melanogaster ◽  
Dominant Gene ◽  
Crossing Over ◽  
Linkage Equilibrium ◽  
Selection Experiment ◽  
Base Population ◽  
Response To Selection ◽  
Wild Type ◽  
Segregation Ratios

SUMMARYA selection experiment for sternopleural bristles in Drosophila melanogaster was undertaken to measure the effect of suppressing crossing-over on chromosomes II and III using the inversions Curly and Moiré marked with a dominant gene, which severely reduce crossing-over. In one set of lines selected wild-type males were mated to selected females, heterozygous for Cy and Mé, and in a parallel set selected males carrying the inversions were mated to selected wild-type females. Because there is no crossing-over in the males in this species, crossing-over is much reduced in the first set and is at its usual level in the second. The effect of the selection was measured on flies which did not carry the inversions. The suppression of crossing-over reduced the advance at the limit by 28 ± 8% for selection upwards and by 22 ± 7% for selection downwards. The segregation ratios of the inversions were observed throughout the experiment. At the end, the proportion of wild-type flies emerging was not different in the two sets of lines. The results are consistent with an assumption of initial linkage equilibrium between loci affecting sternopleural bristles in the base population.

PREFERENTIAL PAIRING OF CHROMOSOMES IN A TETRAPLOID HYBRID BETWEEN ORYZA GLABERRIMA AND O. SATIVA

1968 ◽  
Vol 10 (3) ◽  
pp. 527-535 ◽  
Author(s):  
Hiko-Ichi Oka
Keyword(s):  
Oryza Sativa ◽  
Oryza Sativa L ◽  
Oryza Glaberrima ◽  
Tetraploid Species ◽  
Preferential Pairing ◽  
Tetraploid Hybrid ◽  
Segregation Ratios ◽  
Gametic Selection ◽  
High Degree ◽  
Species Hybrids

A tetraploid hybrid was obtained from a cross between induced tetraploid strains of Oryza sativa L. and O. glaberrima Steud., which differed in glutinous (waxy) vs. non-glutinous starch (gl: +) and other genes. In the hybrid, as compared with the parental strains, there was a reduced number of quadricvalents and a relatively high degree of fertility. Segregation ratios for the glutinous gene observed in the back-cross and F2 generation appeared to be modified not only by preferential homogenetic pairing but also by gametic selection. Taking into account the effect of gametic selection estimated from simplex heterozygotes, it was suggested that preferential pairing could take place to a certain extent. It seems to be difficult to measure quantitatively the degree of preferential pairing in tetraploid species hybrids, unless the effect of various segregation-distorting factors can be accounted for.

Aquatic hyphomycetes from different substrates: substrate preference and seasonal occurrence

1992 ◽  
Vol 43 (2) ◽  
pp. 491 ◽  
Author(s):  
K Thomas ◽  
GA Chilvers ◽  
RH Norris
Keyword(s):  
Riparian Vegetation ◽  
Fungal Species ◽  
Aquatic Hyphomycetes ◽  
Substrate Availability ◽  
Fungal Flora ◽  
Substrate Preferences ◽  
Eucalyptus Viminalis ◽  
Minimum Number ◽  
High Degree ◽  
Species Being

Aquatic hyphomycetes occurring in an Australian upland stream (Lees Creek) were sampled from naturally submerged substrates derived from the riparian vegetation. Substrates sampled were bark and phyllodes of Acacia melanoxylon; bark, leaves and twigs of Eucalyptus viminalis; leaves of Pomaderris aspera; fronds of a fern, Blechnum nudum; and leaves of a sedge, Cyperus sp. A total of 47 species of hyphomycetes was detected overall, with maximum subsets of 34 species being recorded from eucalypt twigs and sedge leaves and the minimum number of 28 species being recorded from eucalypt leaves. The fungi showed significant substrate preferences, although no species was confined to a single substrate. Possible reasons for substrate preferences are advanced. The patterns of occurrence of the various fungal species were sufficiently distinct that most substrates could be predicted with a high degree of success from a knowledge of the fungal flora sampled from them. Patterns of occurrence varied with season, probably influenced by changing substrate availability and water temperature.

Revisiting the evolution of the North American tetraploid treefrog (Hyla versicolor)

Genome ◽  
2020 ◽  
Vol 63 (11) ◽  
pp. 547-560 ◽  
Author(s):  
James P. Bogart ◽  
Patrick Burgess ◽  
Jinzhong Fu
Keyword(s):  
Diploid Species ◽  
Hyla Versicolor ◽  
Hyla Chrysoscelis ◽  
Gene Exchange ◽  
Tetraploid Species ◽  
Sympatric Populations ◽  
Female Progeny ◽  
The North ◽  
Mating Call ◽  
Mitochondrial Cytochrome B

Hyla chrysoscelis and H. versicolor are common treefrogs in eastern North America and are a cryptic diploid–tetraploid species pair. They are morphologically identical but H. versicolor is a tetraploid. They can be identified acoustically by the male’s advertisement mating call, which has a pulse repetition rate that has twice as many pulses per second in the diploid species, H. chrysoscelis. We used isozymes, microsatellite DNA alleles, and mitochondrial cytochrome b sequences to test the hypothesis that gene exchange occurs between the diploid and tetraploid species in sympatric populations. Each method provided results that are best explained by occasional hybridization of female H. versicolor and male H. chrysoscelis. We propose that H. versicolor first arose from an autotriploid H. chrysoscelis female that produced unreduced triploid eggs. After H. versicolor became established, genes could be passed from H. chrysoscelis to H. versicolor in sympatric populations when these species hybridize. Their F1 female progeny produce unreduced triploid eggs that are fertilized by haploid H. chrysoscelis sperm to reconstitute H. versicolor. Genes can be passed from diploid H. chrysoscelis to tetraploid H. versicolor in sympatric populations.

scholarly journals Detection and Characterization of Genome-specific Microsatellite Markers in the Allotetraploid Prunus serotina

2008 ◽  
Vol 133 (3) ◽  
pp. 390-395 ◽  
Author(s):  
Marie Pairon ◽  
Anne-Laure Jacquemart ◽  
Daniel Potter
Keyword(s):  
Microsatellite Markers ◽  
Null Allele ◽  
Prunus Serotina ◽  
Specific Primers ◽  
Genetic Studies ◽  
Expected Heterozygosity ◽  
Disomic Inheritance ◽  
Successful Amplification ◽  
Potential Use

The utility of microsatellite markers to characterize the genetic diversity of a polyploid species with disomic inheritance is often hampered by the impossibility of determining allele frequencies and the complexity of inheritance patterns. The objective of this study was to solve these problems in the allotetraploid Prunus serotina Ehrh. by finding genome-specific primers (i.e., primers that are specific to one of the two genomes that initially formed the species). Sixty-seven microsatellite primers described in cultivated Prunus L. species were tested for cross-amplification in P. serotina, and evidence that conserved markers were genome-specific was found by demonstrating their typical Mendelian diploid inheritance in embryos resulting from controlled crosses. Among the 67 microsatellite markers tested, 26 produced successful amplification and five were genome-specific. No linkage disequilibrium was detected for these loci, but evidence was found for the presence of a null allele at one locus. We found both a high number of alleles per locus (three to 12) and a high mean expected heterozygosity (0.71), which were nonsignificantly different from the number of alleles and estimates of expected heterozygosity calculated for three non-genome-specific markers in the same population. The potential use of these genome-specific markers in population genetic studies is discussed.

Peroxidase Isoenzyme Variation in Interspecific Elm Hybrids

1972 ◽  
Vol 2 (3) ◽  
pp. 264-270 ◽  
Author(s):  
Peter P. Feret
Keyword(s):  
Segregation Distortion ◽  
Close Correlation ◽  
Crossing Over ◽  
Peroxidase Isoenzymes ◽  
Mendelian Segregation ◽  
Peroxidase Isoenzyme ◽  
Segregation Ratios ◽  
Isoenzyme Variation

Analysis of peroxidase isoenzymes in interspecific elm hybrids indicated that a close correlation exists between parental isoenzymes and those of the progeny. In some crosses, isoenzymes undergo mendelian segregation while in others segregation distortion is evident. Mechanisms proposed to account for the disturbed segregation ratios and unexpected phenotypes include crossing over between peroxidase loci, accumulation of lethal genetic deficiencies, and dominance of some peroxidase genes.

scholarly journals Initiation of Antenatal Care and Number of Antenatal Visit among the Pregnant Women of Savar, Dhaka

2019 ◽  
pp. 1-4
Author(s):  
Shamima Nasrin Shadia ◽  
◽  
Sadia Afrin ◽  
Ken Yoshimura ◽  
Moazzem Hossain ◽  
...  
Keyword(s):  
Antenatal Care ◽  
Pregnant Women ◽  
General Hospital ◽  
Antenatal Visit ◽  
Adequate Knowledge ◽  
Late Initiation ◽  
Minimum Number ◽  
Study Population

Antenatal care (ANC) is a care given to pregnant women to timely identify and mitigate pregnancy related problems that can harm mother and/or fetus. Most of the Bangladeshi women present late for ANC. This study aims to determine the time of ANC initiation and the number of visit for ANC among pregnant women attending Filaria & General Hospital between January 2016 and December 2018. The study population had adequate knowledge regarding ANC except for pregnant women who had visited minimum number for ANC. Among 1761 study population, 1268 (72%) had registered for ANC, and 493(28%) had not registered. Out of 1268, 651 (51.34%) had their first ANC within the recommended time (before or at three months), and 617(48.66%) started late initiation of their ANC care. Here, 649 (51.18%) of the study population received more than three visits for ANC.

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