scholarly journals The Drosophila fertility factor kl-3 is linked to the Y-chromosome of the vector of Chagas’ disease Triatoma infestans (Hemiptera: Reduviidae) and is essential for male fertility

2019 ◽  
Author(s):  
Carlos H. Martins ◽  
Rodrigo S. V. P da Silva ◽  
Thalia K. Ferreira ◽  
Rafaela Paim ◽  
Grasielle C. D. Pessoa ◽  
...  

AbstractIn many insects, the Y chromosome plays a key role in sexual determination and male fertility. The Chagas disease vector Triatoma infestans has 22 autosomal chromosomes and a pair of XY sex chromosomes. However, the knowledge on the Y chromosome of this species, its genetic content or its biological function, is very poor. Due to repetitive DNA, Y chromosome sequences are poorly assembled in genome projects, hindering structural and functional studies on Y-linked genes. Our group has developed many of the bioinformatic tools to identify Y-linked sequences in assembled genomes. Here, we describe the identification of a γ-dynein heavy chain linked to the Y-chromosome of T. infestans. This protein is orthologous to the Drosophila melanogaster Y-linked gene kl-3. In D. melanogaster, dyneins of the Y chromosome are known as male fertility factors and their deletion causes male infertility. We performed knockdown of the kl-3 expression to ascertain its function in T. infestans. Our results showed that injection of dsKL3 reduced, significantly, the fertility of T. infestans males (p<0.01). The mean number of eggs laid by the control group was 35.64 eggs/couple while the kl-3 knockdown group was of 11.82 eggs/couple (five couples did not lay any eggs). Differences in eclosion rate was even more significant, with a hatching mean rate of 16.85±10.03 and 1.69±3.58 (p<0.001) for the control and the silenced groups respectively. Our results suggest that kl-3 maintains its functional role as essential for male fertility in T. infestans. Hence, it seems that the Y-chromosome of T. infestans has a key role in male fertility. This is the first report of a kl-3 orthologue linked to the Y chromosome of an insect species outside the diptera clade. In addition to the first report of a Y-linked gene in T. infestans with a role for male fertility, this finding is of great relevance for the study of the evolution of Y chromosomes and further studies that could lead to novel approaches in insect control.

Genome ◽  
1992 ◽  
Vol 35 (6) ◽  
pp. 1068-1074 ◽  
Author(s):  
Fco Panzera ◽  
F. Alvarez ◽  
J. Sanchez-Rufas ◽  
R. Pérez ◽  
J. A. Suja ◽  
...  

This is the first report of intraspecific variation of C-bands in Heteroptera, described in natural populations of Triatoma infestans (Hemiptera: Reduviidae), the main vector of Chagas disease in Uruguay. Marked variation in number, position, and size of C-heterochromatic bands was found in the three large autosomal pairs. A geographical pattern of this chromosomal polymorphism was observed. Evolutionary importance and epidemiological relevance are discussed.Key words: Triatoma infestans, cytogenetics, C-band polymorphism, holocentric chromosomes, Chagas disease.


Author(s):  
Nabil A. Khouri ◽  
Haytham M. Daradka ◽  
Mohammed Z. Allouh ◽  
Ahmad S. Alkofahi

Abstract: The effects of: Both plants were administered orally to two separate mice groups at a dose of 800 mg/kg/day for 35 days and compared with control group. After treatment, 5 mice of each group were sacrificed and total mice weights, reproductive organs’ weights, spermatogenesis, and androgenic serum markers were investigated. The remaining mice from all groups were allowed to mate with virgin female mice to explore male fertility potential.: Results indicated that body and organs’ weights were increased significantly in mice treated with: We can conclude that


Author(s):  
Raquel Gonçalves ◽  
Daniel Landivar ◽  
Edson Grover Sañez Liendo ◽  
Janet Mamani Fernandez ◽  
Hanafy M. Ismail ◽  
...  

Genetics ◽  
1996 ◽  
Vol 142 (2) ◽  
pp. 437-446
Author(s):  
Ron Hochstenbach ◽  
Harry Harhangi ◽  
Karin Schouren ◽  
Petra Bindels ◽  
Ron Suijkerbuijk ◽  
...  

Abstract We have found that defective gypsy retrotransposons are a major constituent of the lampbrush loop pair Nooses in the short arm of the Y chromosome of Drosophila hydei. The loop pair is formed by male fertility gene Q during the primary spermatocyte stage of spermatogenesis, each loop being a single transcription unit with an estimated length of 260 kb. Using fluorescent in situ hybridization, we show that throughout the loop transcripts gypsy elements are interspersed with blocks of a tandemly repetitive Y-specific DNA sequence, ay1. Nooses transcripts containing both sequence types show a wide size range on Northern blots, do not migrate to the cytoplasm, and are degraded just before the first meiotic division. Only one strand of ay1 and only the coding strand of gypsy can be detected in the loop transcripts. However, as cloned genomic DNA fragments also display opposite orientations of ay1 and gypsy, such DNA sections cannot be part of the Nooses. Hence, they are most likely derived from the flanking heterochromatin. The direction of transcription of ayl and gypsy thus appears to be of a functional significance.


1978 ◽  
Vol 27 ◽  
pp. 51-56 ◽  
Author(s):  
Fiorella Shabtai ◽  
Shlomo Bichacho ◽  
Isaac Halbrecht

The negative influence of some insecticides on male fertility has been noted. We report our cytogenetic observations on a group of infertile insecticide workers. Increased chromosomal breakage was a constant finding and the Y chromosome was especially damaged. This may account for impaired spermatogenesis. Furthermore, the involvement of heterochromatic chromosomal variants both in the individual susceptibility to the chemically induced damage and in the reproductive fitness is emphasized.


BMC Urology ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Hassan Osman Alhassan Elsaid ◽  
Tarteel Gadkareim ◽  
Tagwa Abobakr ◽  
Eiman Mubarak ◽  
Mehad A. Abdelrhem ◽  
...  

Abstract Background Male factor is the major contributor in roughly half of infertility cases. Genetic factors account for 10–15% of male infertility. Microdeletions of azoospermia factors (AZF) on the Yq region are the second most frequent spermatogenesis disorder among infertile men after Klinefelter syndrome. We detected in our previous study a frequency of 37.5% AZF microdeletions which investigated mainly the AZFb and AZFc. We attempted in this study for the first time to evaluate the frequencies of all AZF sub-regions microdeletions and to analyze reproductive hormonal profiles in idiopathic cases of azoospermic and oligozoospermic men from Sudan. Methods A group of 51 medically fit infertile men were subjected to semen analysis. Four couples have participated in this study as a control group. Semen analysis was performed according to WHO criteria by professionals at Elsir Abu-Elhassan Fertility Centre where samples have been collected. We detected 12 STSs markers of Y chromosome AZF microdeletions using a multiplex polymerase chain reaction. Analysis of reproductive hormone levels including Follicle Stimulating, Luteinizing, and Prolactin hormones was performed using ELISA. Comparisons between outcome groups were performed using Student’s t-test Chi-square test or Fisher’s exact test. Results AZF microdeletion was identified in 16 out of 25 Azoospermic and 14 out of 26 of the Oligozoospermic. Microdeletion in the AZFa region was the most frequent among the 30 patients (N = 11) followed by AZFc, AZFd (N = 4 for each) and AZFb (N = 3). Among the Oligozoospermic participants, the most frequent deletions detected were in the AZFa region (N = 10 out of 14) and was significantly associated with Oligozoospermic phenotype, Fisher's Exact Test (2-sided) p = 0.009. Among the Azoospermic patients, the deletion of the AZFc region was the most frequent (N = 9 out of 16) and was significantly associated with Azoospermia phenotype Fisher's Exact Test p = 0.026. There was a significant difference in Y chromosome microdeletion frequency between the two groups. The hormonal analysis showed that the mean levels of PRL, LH, and FSH in Azoospermic patients were slightly higher than those in oligozoospermic. A weak negative correlation between prolactin higher level and Azoospermic patients was detected. (AZFa r = 0.665 and 0.602, p = 0.000 and 0.0004, AZFb r = 0.636 and 0.409, p = 0.000 and 0.025, and AZFd r = 0.398 and 0.442, p = 0.029 and 0.015). The correlation was positive for AZFa and negative for AZFb and AZFd. Conclusions We concluded in this study that the incidences of microdeletions of the Y chromosome confined to AZF a, b, c and d regions is 58.8% in infertile subjects with 31.4% were Azoospermic and 27.5% were Oligozoospermic. This might provide a piece of evidence that these specified regions of the Y chromosome are essential for controlling spermatogenesis. These findings will be useful for genetic counseling within infertility clinics in Sudan and to adopt appropriate methods for assisted reproduction.


2013 ◽  
Vol 14 (5) ◽  
pp. 316-323 ◽  
Author(s):  
Beatriz García ◽  
Alicia R. Pérez Rosas ◽  
María Blariza ◽  
Carla Grosso ◽  
Cintia Fernández ◽  
...  

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