scholarly journals Insights about variation in meiosis from 31,228 human sperm genomes

2019 ◽  
Author(s):  
Avery Davis Bell ◽  
Curtis J. Mello ◽  
James Nemesh ◽  
Sara A. Brumbaugh ◽  
Alec Wysoker ◽  
...  

AbstractMeiosis, while critical for reproduction, is also highly variable and error prone: crossover rates vary among humans and individual gametes, and chromosome nondisjunction leads to aneuploidy, a leading cause of miscarriage. To study variation in meiotic outcomes within and across individuals, we developed a way to sequence many individual sperm genomes at once. We used this method to sequence the genomes of 31,228 gametes from 20 sperm donors, identifying 813,122 crossovers, 787 aneuploid chromosomes, and unexpected genomic anomalies. Different sperm donors varied four-fold in the frequency of aneuploid sperm, and aneuploid chromosomes gained in meiosis I had 36% fewer crossovers than corresponding non-aneuploid chromosomes. Diverse recombination phenotypes were surprisingly coordinated: donors with high average crossover rates also made a larger fraction of their crossovers in centromere-proximal regions and placed their crossovers closer together. These same relationships were also evident in the variation among individual gametes from the same donor: sperm with more crossovers tended to have made crossovers closer together and in centromere-proximal regions. Variation in the physical compaction of chromosomes could help explain this coordination of meiotic variation across chromosomes, gametes, and individuals.


Genetics ◽  
1989 ◽  
Vol 123 (1) ◽  
pp. 81-95 ◽  
Author(s):  
E J Louis ◽  
J E Haber

Abstract The presence of the tRNA ochre suppressors SUP11 and SUP5 is found to induce meiosis I nondisjunction in the yeast Saccharomyces cerevisiae. The induction increases with increasing dosage of the suppressor and decreases in the presence of an antisuppressor. The effect is independent of the chromosomal location of SUP11. Each of five different chromosomes monitored exhibited nondisjunction at frequencies of 0.1%-1.1% of random spores, which is a 16-160-fold increase over wild-type levels. Increased nondisjunction is reflected by a marked increase in tetrads with two and zero viable spores. In the case of chromosome III, for which a 50-cM map interval was monitored, the resulting disomes are all in the parental nonrecombinant configuration. Recombination along chromosome III appears normal both in meioses that have no nondisjunction and in meioses for which there was nondisjunction of another chromosome. We propose that a proportion of one or more proteins involved in chromosome pairing, recombination or segregation are aberrant due to translational read-through of the normal ochre stop codon. Hygromycin B, an antibiotic that can suppress nonsense mutations via translational read-through, also induces nonrecombinant meiosis I nondisjunction. Increases in mistranslation, therefore, increase the production of aneuploids during meiosis. There was no observable effect of SUP11 on mitotic chromosome nondisjunction; however some disomes caused SUP11 ade2-ochre strains to appear white or red, instead of pink.



Author(s):  
Ayo Wahlberg

From crude and uneasy beginnings, sperm banking has become a routine part of China’s pervasive and restrictive reproductive complex within the space of thirty years. It covers the introduction of assisted reproductive technologies (ARTs) to China to address infertility, the expansion of the use of donor sperm in cases in which the male partner suffers from a genetic disease, and other issues, such as the availability and screening of potential sperm donors.



1997 ◽  
Vol 101 (1) ◽  
pp. 61-66 ◽  
Author(s):  
C. L. O'Keefe ◽  
D. K. Griffin ◽  
Christopher J. Bean ◽  
A. Gregory Matera ◽  
T. J. Hassold
Keyword(s):  


PLoS ONE ◽  
2011 ◽  
Vol 6 (3) ◽  
pp. e18095 ◽  
Author(s):  
Maja D. Kaspersen ◽  
Peter B. Larsen ◽  
Hans Jakob Ingerslev ◽  
Jens Fedder ◽  
Gert Bruun Petersen ◽  
...  
Keyword(s):  


2020 ◽  
Vol 46 (7) ◽  
pp. 489-492 ◽  
Author(s):  
Nathan Hodson ◽  
Joshua Parker

In this article we outline and defend the concept of voluntary non-directed postmortem sperm donation. This approach offers a potential means of increasing the quantity and heterogeneity of donor sperm. This is pertinent given the present context of a donor sperm shortage in the UK. Beyond making the case that it is technically feasible for dead men to donate their sperm for use in reproduction, we argue that this is ethically permissible. The inability to access donor sperm and the suffering this causes, we argue, justifies allowing access to sperm donated after death. Moreover, it is known that individuals and couples have desires for certain sperm donor characteristics which may not be fulfilled when numbers of sperm donors are low. Enacting these preferences contributes significantly to the well-being of intended parents, so we argue that this provides a pro tanto reason for respecting them. Finally, we explore the benefits and possible disadvantages of such a system for the various parties affected.



2021 ◽  
Author(s):  
Junjie Liu ◽  
Yanpeng Dai ◽  
Yushan Li ◽  
Enwu Yuan ◽  
Quanxian Wang ◽  
...  

Abstract STUDY QUESTION Is there a relation between the characteristics of potential sperm donors and the acceptance rate of these potential donors? SUMMARY ANSWER A relatively higher acceptance rate was observed for potential sperm donors who were aged ≤ 35 years, were married, had children, and who had received higher education, and acceptance rates were also higher during spring and winter than summer and autumn. WHAT IS KNOWN ALREADY Recruiting donors to a sperm bank program is difficult and slow owing to the high rates of rejection and dropout. STUDY DESIGN, SIZE, DURATION A total of 24040 potential sperm donors were screened by the Henan Human Sperm Bank from 2006 to 2019. PARTICIPANTS/MATERIALS, SETTING, METHODS Potential sperm donors were recruited using the following baseline requirement: height of 168 cm or taller; age 22-45 years; currently attending or had graduated from high school or above. Men who met the criteria for age, height, and education level were invited for semen quality screening. The acceptable criteria for semen samples included liquefaction time < 60min, volume ≥ 2mL, sperm concentration ≥ 60 × 106/mL, progressive motility ≥ 60%, post-thaw motility ≥ 40%, pre-freezing total motile sperm per vial > 30 × 106/mL, post-thaw total motile sperm per vial > 12 × 106/mL, and freeze-thaw survival rate ≥ 60%. Any potential sperm donors meeting the minimum criteria for acceptable semen quality on two consecutive semen samples were scheduled for clinical assessment, physical examination, and laboratory tests. The reasons for sperm donor rejection were analyzed. The characteristics of accepted and rejected donors were compared using the chi-square test, and multivariate logistic regression analyses were conducted to identify factors associated with the acceptance rate of potential sperm donors and the positive rate of sexually transmitted diseases (STDs). MAIN RESULTS AND THE ROLE OF CHANCE Only 23.38% (5620/24040) of potential sperm donors were accepted. The top four reasons for rejection were suboptimal semen quality (90.27%), STDs (6.26%), dropped out (2.65%), and chromosomal abnormalities (0.35%). The most common reason for the rejection of donors with an STD was a positive test for mycoplasmas (49.05%), followed by hepatitis B virus (27.56%), Chlamydia trachomatis (4.68%), and Escherichia coli (3.03%). n this study, the acceptance rate for men aged ≤ 35 years was significantly higher than that for men aged >35 years (P < 0.05). The acceptance rates were also significantly higher for men with a higher education than for men with lower education, married men than unmarried men, and men with children than men without children (P < 0.05). Moreover, acceptance rates were significantly higher during spring and winter than during summer (P <0.05) but were not significantly higher during autumn than during summer (P >0.05). LIMITATIONS, REASONS FOR CAUTION This study was not performed to analyze the effect of lifestyle habits, such as alcohol consumption and cigarette smoking, on the acceptance rate of potential sperm donors. WIDER IMPLICATIONS OF THE FINDINGS Only a small proportion of potential sperm donors were accepted in this anonymous sperm donor program. New strategies for sperm donor recruitment may be required to improve the acceptance rate. In the future, we may have to target potential sperm donors who are aged ≤ 35 years and who received higher education in order to improve the acceptance rate. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by the Joint Construction Project of Henan Medical Science and Technology Research Plan under grant number LHGJ20190389. The authors report no conflict of interest. TRIAL REGISTRATION NUMBER N/A



Author(s):  
A. Sosa ◽  
L. Calzada

The dependence of nuclear metabolism on the function of the nuclear membrane is not well understood. Whether or not the function of the nuclear membrane is partial or totally responsible of the repressed template activity of human sperm nucleus has not at present been elucidated. One of the membrane-bound enzymatic activities which is concerned with the mechanisms whereby substances are thought to cross cell membranes is adenosintriphosphatase (ATPase). This prompted its characterization and distribution by high resolution photogrammetry on isolated human sperm nuclei. Isolated human spermatozoa nuclei were obtained as previously described. ATPase activity was demonstrated by the method of Wachstein and Meisel modified by Marchesi and Palade. ATPase activity was identified as dense and irregularly distributed granules confined to the internal leaflet of the nuclear membrane. Within the nucleus the appearance of the reaction product occurs as homogenous and dense precipitates in the interchromatin space.



2020 ◽  
Vol 64 (2) ◽  
pp. 251-261
Author(s):  
Jessica E. Fellmeth ◽  
Kim S. McKim

Abstract While many of the proteins involved in the mitotic centromere and kinetochore are conserved in meiosis, they often gain a novel function due to the unique needs of homolog segregation during meiosis I (MI). CENP-C is a critical component of the centromere for kinetochore assembly in mitosis. Recent work, however, has highlighted the unique features of meiotic CENP-C. Centromere establishment and stability require CENP-C loading at the centromere for CENP-A function. Pre-meiotic loading of proteins necessary for homolog recombination as well as cohesion also rely on CENP-C, as do the main scaffolding components of the kinetochore. Much of this work relies on new technologies that enable in vivo analysis of meiosis like never before. Here, we strive to highlight the unique role of this highly conserved centromere protein that loads on to centromeres prior to M-phase onset, but continues to perform critical functions through chromosome segregation. CENP-C is not merely a structural link between the centromere and the kinetochore, but also a functional one joining the processes of early prophase homolog synapsis to late metaphase kinetochore assembly and signaling.





1998 ◽  
Vol 5 (1) ◽  
pp. 107A-107A
Author(s):  
A EBLEN ◽  
S BAO ◽  
Z LEI ◽  
J SANFILIPPO ◽  
C RAO


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