New Role for an Old Protein: An Educational Primer for Use with "The Identification of a Novel Mutant Allele of topoisomerase II in Caenorhabditis elegans Reveals a Unique Role in Chromosome Segregation During Spermatogenesis".

Modern experimental techniques, such as whole-genome sequencing and clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 endogenous genome editing, are enabling researchers to identify and further characterize the roles of proteins that were previously thought of as well defined. In the December 2016 issue of GENETICS, an article by Jaramillo-Lambert et al. identified a new role for the enzyme topoisomerase II in Caenorhabditis elegans male meiosis. This Primer article is designed to provide essential background information on C. elegans spermatogenesis and the relevant scientific techniques that will assist students and instructors in their understanding and discussion of the related article.Related article in GENETICS: Jaramillo-Lambert, A., A. S. Fabritius A. S., T. J. Hansen T. J., H. E. Smith H. E., and A. Golden A., 2016 The identification of a novel mutant allele of topoisomerase II in Caenorhabditis elegans reveals a unique role in chromosome segregation during spermatogenesis. Genetics204: 1407-1422.

Testicular cells exhibit similar molecular responses to cigarette smoke condensate ex vivo and in vivo.

Male exposure to cigarette smoke is associated with seminal defects and with congenital anomalies and childhood cancers in offspring. In mice, paternal exposure to cigarette smoke condensate (CSC) causes molecular defects in germ cells and phenotypic effects in their offspring. Here we used an ex vivo testicular explant model and in vivo exposure to determine the concentration at which CSC impairs spermatogenesis and offspring development. We explanted testis tissue at postnatal day (P)5.5 and cultured it until P11.5. Assessment of growth parameters by analyzing expression of cell-specific markers revealed that the explant system maintained structural and functional integrity. We exposed the P5.5 to -11.5 explants to various concentrations (40-160 µg/ml) of CSC and confirmed that nicotine in the CSC was metabolized to cotinine. We assessed various growth and differentiation parameters, as well as testosterone production, and observed that many spermatogenesis features were impaired at 160 µg/ml CSC. The same parameters were impaired by a similar CSC concentration in vivo Finally, females mated to males that were exposed to 160 µg/ml CSC neonatally had increased rates of pup resorption. We conclude that male exposure to CSC impairs offspring development and that the concentration at which CSC impairs spermatogenesis is similar in vivo and ex vivo. Given that the concentrations of CSC we used contained similar doses of nicotine as human smokers are exposed to, we argue that our model mimics human male reproductive effects of smoking.-Esakky, P., Hansen, D. A., Drury, A. M., Felder, P., Cusumano, A., Moley, K. H. Testicular cells exhibit similar molecular responses to cigarette smoke condensate ex vivo and in vivo.

Cytology of testicular changes in leprosy.

OBJECTIVE: To study the changes in testicular aspirates and semen of patients with leprosy. STUDY DESIGN: A prospective study of 56 patients in the reproductive-age group, with no record of treatment for leprosy. Both Ridley-Jopling and WHO classification systems were used. Skin and/or nerve biopsies were performed for documentation of the diagnosis. Semen analysis and fine needle aspirates of the testes were performed. Smears from the testicular aspirates were stained with May-Grünwald-Giemsa and Ziehl-Neelsen stain. RESULTS: Five patients were unable to produce an ejaculate. Abnormal semen analysis and/or testicular aspirates were seen in 24 (42.8%) patients. Eleven had oligospermia and eight azoospermia. Abnormalities in testicular aspirates ranged from hypospermatogenesis (4) through maturation arrest (1) and atrophy (11). Two patients had hydrocoele, and two had associated microfilariae. Three patients with multibacillary leprosy had type 2 reaction. Mycobacterium lepre was demonstrable in testicular aspirates from all patients with multibacillary and in three with paucibacillary leprosy. CONCLUSION: Abnormal semen analysis and/or testicular aspirates occur in a very high percentage of patients with leprosy. While this is expected for multibacillary disease, the high incidence in the paucibacillary form was surprising. With the rapid elimination of leprosy, fertility-related disability might emerge as a major problem in these people.

The leprous testis.

A clinical investigative study of 148 male leprous patients demonstrated the presence of testicular lesions in 35 cases. Semen analysis revealed marked oligo-athenozoospermia in 10 cases and azoospermia in 25 cases. Testicular biopsies from leprous testes showed different histologic patterns ranging from spermatogenic arrest to complete hyalinization of both seminiferous tubules and interstitial tissue. Histochemical staining for neurovascular supply revealed degenerative nerve change in addition to altered permeability of the testicular capillaries. There was good correlation between the results of semen analysis and histological and histochemical examination of testicular biopsies.

Testicular and epididymal involvement in leprosy patients, with special reference to gynecomastia

Sixty-six male patients with leprosy were studied. Only those with the lepromatous type developed testicular and epididymal changes. Nine of the 38 patients showed decreased sexual function, and 7 developed gynecomastia. These changes were believed to be due to the altered gonadal state.

Testicular and epididymal involvement in leprosy patients, with special reference to gynecomastia.

Sixty-six male patients with leprosy were studied. Only those with the lepromatous type developed testicular and epididymal changes. Nine of the 38 patients showed decreased sexual function, and 7 developed gynecomastia. These changes were believed to be due to the altered gonadal state.

Immunologic studies of male infertility.

Infertile men with azo- or oligospermia of unknown cause were investigated for evidence of testicular autoimmunity. Testicular germinal cell antibodies were found in 14% of the patients, compared with 5% of normal men, and 21% had spermatozoal antibodies, compared with 5% of the normal subjects. One-third had positive macrophage inhibitory factor tests, compared with 5% of normal subjects. However, of autoantibodies against thyroid, stomach, and nuclear material, only the prevalence of thyroid cytoplasmic antibodies was significantly greater than in normal subjects; serum IgG, IgM, and IgA levels were normal in all cases tested. Furthermore, there was no excess of lymphoid tissue on biopsy and no evidence of antibody deposition in the testicular tissue. The evidence for autoimmunity is less impressive than that for leprous orchitis, which has been proposed as a model for testicular organ-specific autoimmunity. Nevertheless, it is possible that certain germinal cell or spermatozoal antibodies may be directed against factors necessary for orderly spermatogenesis. If so, they may play a role in some cases of maturation arrest and shedding defects.