Major chromosomal length polymorphisms are evident after meiosis in the phytopathogenic fungus Leptosphaeria maculans

1993 ◽  
Vol 24 (1-2) ◽  
pp. 107-113 ◽  
Author(s):  
Kim M. Plummer ◽  
Barbara J. Howlett
Keyword(s):  
Leptosphaeria Maculans ◽  
Phytopathogenic Fungus ◽  
Length Polymorphisms ◽  
Chromosomal Length Polymorphisms ◽  
Chromosomal Length

scholarly journals Evaluation of Chromosomal Structural Anomalies in Fertility Disorders

Medicina ◽  
2021 ◽  
Vol 57 (1) ◽  
pp. 37
Author(s):  
Danielius Serapinas ◽  
Emilija Valantinavičienė ◽  
Eglė Machtejevienė ◽  
Agnė Bartkevičiūtė ◽  
Daiva Bartkevičienė
Keyword(s):  
Chromosomal Aberrations ◽  
Structural Changes ◽  
Statistical Significance ◽  
Reproductive Disorders ◽  
Miscarriage Rate ◽  
Recurrent Miscarriages ◽  
Length Polymorphisms ◽  
Medical Histories ◽  
Chromosomal Length Polymorphisms ◽  
Chromosomal Length

Background and objectives: Reproductive disorders may occur not only due to environmental factors (air pollution, stressful lifestyle, previous abortions or the use of contraceptives) but also due to genetic factors. Materials and Methods: The aim of the study was to identify the range and frequency of chromosomal aberrations in couples (n = 99) with infertility or recurrent miscarriages in Lithuania. The data were collected from the out-patient medical histories. The couples were divided into three groups based on pregnancy, childbirth and the number of miscarriages. The Chi-square test was used to carry out the statistical analysis, and the statistical significance was (p < 0.05). Results: There were 6.6% (n = 13) structural changes observed in the karyotype tests. Chromosomal aberrations were found in 3% (n = 6) of the subjects, while 3.6% (n = 7) of them had chromosomal length polymorphisms. No difference was found between the aberration frequency in the karyotypes of men and women (p > 0.05). The most common aberrations were balanced translocations (23.1%, n = 3) which accounted for 15.4% of the reciprocal (n = 2) and 7.7% of the Robertsonian type (n = 1) of translocations. The most frequent aberrations were found in couples with the inability to conceive (42.9% (n = 3), p = 0.031). The childless couples and those with recurrent miscarriages showed an aberration rate of 8.2% (n = 5), while in the couples with at least one child it was 16.1% (n = 5). The group of couples unable to conceive had a significantly higher aberration rate of 28.6% (n = 2), p = 0.029. Miscarriages in partners’ families accounted for 8.1%. Miscarriages on the female side of the family accounted for 4.5% (n = 9), on the male side it accounted for 2.5% (n = 5) and on both sides it accounted for 1.1% (n = 2). There were no statistically significant differences observed between the female and male sides (p > 0.05). The miscarriages observed in the second group of couples (childless with ≥2 miscarriages) were more frequent at 18.1% (n = 11), in the third group (having children ≥2 miscarriages) they were less frequent at 12.9% (n = 4), while no miscarriages were recorded in the first group of infertile couples. In total, 3% of the identified significant chromosomal aberrations were likely to trigger miscarriages or the inability to conceive. Conclusions: In couples with reproductive disorders, chromosomal mutations and chromosomal length polymorphisms were found at similar rates: 3% vs. 3.6%. The highest aberration rate was found in couples that were unable to conceive, a lower one was found in a group with children and ≥2 miscarriages, and the lowest one was found in a childless group of subjects with ≥2 miscarriages. The miscarriage rate in partner families was 8.1%; however, no difference was found between the male and female sides.

Detection of additional restriction fragment length polymorphisms among the weakly virulent (nonaggressive) and highly virulent (aggressive) isolates of Leptosphaeria maculans

1995 ◽  
Vol 41 (12) ◽  
pp. 1135-1141 ◽  
Author(s):  
N. A. Patterson ◽  
M. Kapoor
Keyword(s):  
Restriction Fragment ◽  
Fragment Length ◽  
Southern Hybridization ◽  
Leptosphaeria Maculans ◽  
Restriction Fragment Length Polymorphisms ◽  
Additional Restriction ◽  
Gene Probe ◽  
Genetic Characteristics ◽  
Length Polymorphisms ◽  
Restriction Fragment Length

Isolates of Leptosphaeria maculans were analyzed for their genetic relatedness based on DNA restriction fragment length polymorphisms (RFLPs), employing as Southern hybridization probes a combination of heat shock responsive genes (hsp70 and hsp80 from Neurospora crassa), the cutinase gene of Magnaporthe grisea, and cloned genomic DNA sequences from a virulent strain. Southern hybridization analysis revealed a high frequency of DNA polymorphism. Restriction fragments generated by each enzyme-probe combination resulted in distinct banding patterns, clearly separating the isolates into two groups. The cutinase gene probe did not reveal any polymorphisms. Although the majority of the probes used displayed RFLP profiles unique to each group, a nonaggressive isolate, LmA, showed additional genetic characteristics in common with the virulent pathotype.Key words: Leptosphaeria, genomic libraries, RFLP.

scholarly journals Salt Stress Induces Production of Melanin Related Metabolites in the Phytopathogenic Fungus Leptosphaeria Maculans

2009 ◽  
Vol 4 (1) ◽  
pp. 1934578X0900400 ◽  
Author(s):  
M. Soledade C. Pedras ◽  
Yang Yu
Keyword(s):  
Salt Stress ◽  
Pathogenic Fungus ◽  
Leptosphaeria Maculans ◽  
2D Nmr ◽  
Phytopathogenic Fungus ◽  
Chemical Transformations ◽  
Melanin Biosynthesis ◽  
Protection Mechanism ◽  
Chemical Structures ◽  
Stress Metabolites

A search for stress metabolites produced by the plant pathogenic fungus Leptosphaeria maculans (asexual stage Phoma lingam) cultured in high salt medium led to the isolation and structure elucidation of two metabolites associated with melanin biosynthesis and cell melanization, a self-protection mechanism against salt stress. The chemical structures of the metabolites were deduced by detailed analysis of 1D and 2D NMR spectroscopic data and chemical transformations.

scholarly journals New Avirulence Genes in the Phytopathogenic Fungus Leptosphaeria maculans

2002 ◽  
Vol 92 (10) ◽  
pp. 1122-1133 ◽  
Author(s):  
M. H. Balesdent ◽  
A. Attard ◽  
M. L. Kühn ◽  
T. Rouxel
Keyword(s):  
Gene Cluster ◽  
Oilseed Rape ◽  
Single Gene ◽  
Leptosphaeria Maculans ◽  
Phytopathogenic Fungus ◽  
Gene Control ◽  
Avirulence Genes ◽  
Avr Gene ◽  
Avr Genes

Leptosphaeria maculans, the causal agent of stem canker of oilseed rape (Brassica napus), develops gene-for-gene interactions with oilseed rape, and four L. maculans avirulence (AVR) genes (AvrLm1, AvrLm2, AvrLm4, and alm1) were previously genetically characterized. Based on the analysis of progeny of numerous in vitro crosses between L. maculans isolates showing either already characterized or new differential interactions, this work aims to provide an overview of the AVR genes that may specify incompatibility toward B. napus and the related species B. juncea and B. rapa. Two novel differential interactions were thus identified between L. maculans and B. napus genotypes, one of them corresponding to a complete resistance to European races of L. maculans. In both cases, a single gene control of avirulence was established (genes AvrLm3 and AvrLm7). Similarly, a single gene control of avirulence toward a B. rapa genotype, also resistant to European L. maculans isolates, was demonstrated (gene AvrLm8). Finally, a digenic control of avirulence toward B. juncea was established (genes AvrLm5 and AvrLm6). Linkage analyses demonstrated that at least four unlinked L. maculans genomic regions, including at least one AVR gene cluster (AvrLm1-AvrLm2-AvrLm6), are involved in host specificity. The AvrLm3-AvrLm4-AvrLm7 region may correspond either to a second AVR gene cluster or to a multiallelic AVR gene.

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