[In vitro spermatogenesis… new horizon to restore fertility?]

The survival of the young boy after cancer has considerably progressed in recent years due to the efficiency of chemo/radiotherapy against the tumor cells. However, this treatment causes adverse effects on healthy tissues, including fertility. Freezing testicular tissue before highly gonadotoxic treatment is a prerequisite for preserving fertility in prepubertal boys that do not produce sperm yet. But which strategy proposes to restore fertility from frozen-thawed testicular tissue? One potential solution would be to consider an in vitro maturation of spermatogonial stem cells. In this article we trace the chronological development of in vitro spermatogenesis that resulted in mouse sperm production in vitro and give an overview of new challenges for the future.

The feasibility of fertility preservation in adolescents with Klinefelter syndrome

STUDY QUESTION

Is fertility preservation feasible after the onset of puberty in adolescents with Klinefelter syndrome (KS)?

SUMMARY ANSWER

Fertility preservation counseling should be an integral part of the care of XXY adolescents. Frozen ejaculated or testicular spermatozoa and even frozen immature germ cells can give them the potential to conceive their genetic progeny. However, no biological or clinical parameters were predictive of mature or immature germ cell retrieval.

WHAT IS KNOWN ALREADY

KS is the commonest sex chromosome disorder observed in azoospermic infertile males. Testicular sperm extraction success decreases with age and after testosterone therapy. Arguably, spermatozoa should be retrieved from KS males at the onset of puberty and before testosterone therapy to increase the chance of success.

STUDY DESIGN, SIZE, DURATION

A retrospective study was performed in eight KS adolescents, aged between 15 and 17 years, who were referred for counseling about their future fertility to the center CECOS (Centre d'Etude et de Conservation des Oeufs et du Sperme humain) at Rouen University Hospital between October 2008 and December 2011.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The patients were first seen with their parents and then separately. It was proposed to them that they should provide a semen sample, if this was azoospermic, two other semen samples spaced by 3 months were collected. If azoospermia was confirmed, a bilateral testicular biopsy was proposed for sperm retrieval and testicular tissue preservation. Each adolescent met the psychologist before undergoing testicular biopsy. Paraffin-embedded testicular tissue was evaluated after staining with hematoxylin-eosin and saffron and immunostaining using vimentin, anti-Müllerian hormone, androgen receptor and MAGE-A4 antibodies. Sertoli cell maturity, germ cell identification and lamina propria alteration were assessed on seminiferous tubules.

MAIN RESULTS AND THE ROLE OF CHANCE

KS adolescents were not deeply concerned about their future fertility and only became involved in the process of fertility preservation after at least three medical consultations. The parents agreed immediately that fertility preservation should be attempted. Seven non-mosaic XXY adolescents presented with azoospermia and one XXY/XY adolescent had oligozoospermia. Increased plasma levels of FSH and LH as well as bilateral testicular hypotrophy were observed in all patients. The XXY/XY adolescent banked four semen samples before testosterone replacement therapy. Two patients refused testicular biopsy. Five patients accepted a bilateral testicular biopsy. Spermatozoa were retrieved in one patient, elongated spermatids and spermatocytes I in a second patient.

LIMITATIONS, REASONS FOR CAUTION

The number of patients enrolled in our study was low because the diagnosis of KS is only rarely made before or at the onset of puberty. Most XXY males are diagnosed in adulthood within the context of male infertility.

WIDER IMPLICATIONS OF THE FINDINGS

Spermatozoa can be retrieved in semen sample and in testicular tissue of adolescent Klinefelter patients. Furthermore, the testis may also harbor spermatogonia and incompletely differentiated germ cells. However, the physician should discuss with the patient and his parents over a period of several months before collecting a semen sample and performing bilateral testicular biopsy. Fertility preservation might best be proposed to adolescent Klinefelter patients just after the onset of puberty when it is possible to collect a semen sample and when the patient is able to consider alternative options to achieve fatherhood and also to accept the failure of spermatozoa or immature germ cell retrieval.

Identification and immunohistochemical localization of a haptoglobin-like protein in the tissues and fluids of the bovine (Bos taurus) ovary and oviduct

The objective of this study was to establish the identity of a 40 kDa bovine oviductal fluid protein as a haptoglobin-like protein and to evaluate the association of the haptoglobin-like protein with ovarian and oviductal tissues and fluids. An oviductal fluid protein band corresponding to a molecular mass of 40 kDa was excised and electroeluted from SDS-PAGE gels. Sequence analysis revealed an N-terminal region sharing 81% identity with the beta-subunit of bovine haptoglobin. The 40 kDa oviductal fluid protein crossreacted on immunoblots with antiserum against rabbit endometrial haptoglobin and with an anti-human haptoglobin polyclonal antibody. Two-dimensional PAGE revealed four protein variants ranging in pI from 7.7 to 8.6, which appeared identical, with respect to molecular weight, number of isoforms and pI, to bovine haptoglobin in acute phase serum. The haptoglobin-like protein was localized using immunohistochemistry to the lumina of blood vessels and to the extracellular matrix of ovarian and oviductal tissues. Immunostaining for the haptoglobin-like protein was also detected in the oviductal lumen, in the mucosa of the ampullary oviduct but not the isthmic oviduct, and in intermittent ampullary epithelial cells. Within the ovary, the haptoglobin-like protein was localized to the avascular granulosa cells and follicular fluid of antral follicles, but not in the theca cells or in preantral follicles of any developmental stage. It was concluded that the haptoglobin-like protein is a normal constituent of bovine ovarian and oviductal tissues and fluids, and it was hypothesized that the haptoglobin-like protein contributes to ovarian follicular development and oviductal function.

Influence of capacitation and fluids from the male and female genital tract on the zona binding ability of bull spermatozoa

Before fertilization, inseminated spermatozoa acquire the ability to fertilize an egg, a phenomenon called capacitation. Bovine sperm capacitation is influenced by factors originating from both the male and female genital tract, and results in intracellular and membrane changes of the spermatozoa that facilitate the induction of the acrosome reaction. However, the effects of reproductive tract secretions and capacitation on the binding of spermatozoa to the zona pellucida have not been investigated. In this study, a sperm-egg binding assay was used to determine whether the ability of bull spermatozoa to bind to the zona pellucida was altered during in vitro capacitation by heparin or oviductal fluid, or by treatment of spermatozoa from the cauda epididymidis with accessory sex gland fluid. In addition, biotinylated solubilized zona pellucida proteins were used to visualize zona binding on spermatozoa. The ability of bull spermatozoa to bind to the zona pellucida was increased after both heparin and oviductal fluid induced in vitro capacitation. Exposure of spermatozoa from the cauda epididymidis to accessory sex gland fluid resulted in a direct increase in zona binding ability, followed by a further increase during capacitation in vitro. Binding of solubilized zona proteins was restricted to the acrosomal cap of bull spermatozoa. It is suggested that the observed increased ability of bull spermatozoa to bind to the zona pellucida enables optimal sperm-egg attachment, which also relates to the induction of the acrosome reaction by the zona pellucida. Thus, increased zona binding ability is likely to be an essential part of the process of capacitation.

Contraception and community in Egypt: a preliminary evaluation of the population/development mix

Egypt's Population and Development Program (PDP) is an effort to combine family planning and development approaches at the grass roots level. Introduced as a pilot project in the late 1970s, it is now active in nearly three quarters of Egypt's villages. A 1980 Contraceptive Prevalence Survey of over 5,000 rural women stratified 124 villages according to their exposure to the program (from zero to two or more years). Comparison of women living in villages of varying exposure revealed no differences in fertility; but modest differences in knowledge, attitudes, and contraceptive practice were apparent, especially in Upper Egypt. A multivariate analysis with socioeconomic and demographic controls did not weaken these relationships. Moreover, program effects were most marked among those most in need of services--noncontracepting fecund women who were illiterate.

Heritability and components of phenotypic expression in skin reflectance of Mestizos from the Peruvian lowlands

Skin reflectance was measured on the inner arm and forehead of a sample of 209 Mestizos ranging in age from 2 to 64 years living in the town of Lamas in the Eastern peruvian Lowlands. The sample consisted of 43 father-son, 42 father-daughter, 62 mother-son, and 70 mother-daughter pairs. The sample also consisted of 57 brother-brother, 60 sister-sister and 139 brother-sister pairs. The reflectance measurements were made with a Photovolt Reflection Meter, model 670. Stepwise polynomial regression techniques were used to derive standardized residual values. Then using these residual values parent-offspring, sibling intraclass correlations and components of the phenotype expression of skin reflectance were calculated. The study indicates that 1) the parent-offspring and sibling correlation coefficients conformed with the theoretical correlations expected assuming polygenic inheritance; 2) the husband-wife correlations indicate a high degree of assortative mating for skin color, but despite this effect the parent-offspring and sibling correlation coefficients are lower that the values expected under the influence of autosomal genes; 3) estimates of heritability and components of phenotypic expression indicate that about 55% of the total variability in skin reflectance could be attributed to the influence of additive genetic factors; and 4) there is no evidence of X-linkage in the inheritance of skin color.

Nutritional influence on childhood development and genetic control of adolescent growth of Quechuas and Mestizos from the Peruvian lowlands

The growth in height of 1,202 Quechua and Mestizo children aged 6 to 19 years of the province of Lamas in the Peruvian Eastern Lowlands was studied. As shown by evaluations of ABO, Rh systems, and skin reflectance measurements, the Quechuas are genetically different from the Mestizos. The heights of Quechuas and Mestizos were matched for nutritional status based on measurements of subcutaneous fat and body muscle. The study indicates that: 1) during childhood, Quechuas and Mestizos matched for the same nutritional status attain similar heights; 2) during adolescence (or after the age of 11 years), the Mestizos are significantly taller than the Quechuas of the same nutritional status; 3) during childhood, the relative difference in height between Quechuas and Mestizos matched for the same nutritional status is less than the difference between Quechuas (or Mestizos) of the same genetic composition characterized by good and poor nutritional status. These findings suggest that the influence of environmental factors, such as nutrition, have a greater influence in producing differences in body size during childhood than during adolescence. Conversely, the present findings support the hypothesis that the influence of genetic factors on body size are greater during adolescence than during childhood. However, comparison of adolescent samples of similar genetic composition (whether they be Quechuas or Mestizos), characterized by good and poor nutritional status, reveal large differences in height, suggesting that under conditions of malnutrition, the genetic control of growth is diminished.