Genetics of male infertility: the new players

Approximately 10-15% of couples experience infertility and male factors contribute to half of these cases. It was usually thought that infertility cannot be transmitted, but accumulating evidence indicates that many cases are indeed caused by genetic defects, some inherited. The use of single nucleotide polymorphisms (SNP) arrays allowing to genotype the totality of the genome recently led to identify several genes which, when mutated, generate specific infertility phenotypes. With the tremendous progresses in high throughput sequencing techniques, we can expect many more new genes involved in fertility to be identified in the next years. For the patients concerned, these findings mean the possibility of an accurate diagnosis and improved prognosis. Furthermore, these data will lead to a better understanding of the molecular mechanisms underlying spermatogenesis and thus should contribute to identify and offer new therapeutic strategies for the treatment of infertility.     

Unmanaged care: the need to regulate new reproductive technologies in the United States

In the aftermath of allegations of the misuse of human eggs in the United States, questions are being raised about whether profitable reproductive services should continue to function in a free market under the aegis of physicians or should be regulated. Other countries in which reproductive technologies are employed to a significant degree have developed regulations governing their use, many as a result of recommendations made by inter-disciplinary commissions that solicited public input. Policy makers in the United States have been reluctant to regulate reproductive technologies, however, because their use is politically controversial, they want to whittle down government, some do not consider infertility an illness, and some believe regulation would interfere with the right to reproduce. Yet the unfettered use of reproductive technologies can create such harms as lack of informed consent, providing procedures not medically indicated for financial gain, practice by unqualified personnel, injury to patients and donors, failure to screen donated gametes, and inadequate medical record keeping. Americans place special value on the welfare of children and those who bring them into the world. Such values can outweigh individual procreative liberty when new reproductive technologies are at issue. Although the optimal course would be to establish a regulatory body to govern reproductive technologies, this is not politically feasible now. The newly established National Bioethics Advisory Commission provides a forum in which issues surrounding reproductive technologies should be addressed at this time in the United States.     

A cytogenetic study of Kuwaiti couples with infertility and reproductive disorders: short arm deletion of chromosome 21 is associated with male infertility

Chromosomal anomalies may be a reason for both male and female infertility. The aim of this study was to investigate the contribution of chromosomal abnormalities in sterile couples from Kuwait. A total of 118 patients with clinical diagnosis of infertility was analyzed using cytogenetic banding techniques. Common chromosomal abnormalities were detected in 12 patients. We describe here one new case of an infertile male with the karyotype 46,XY, del(21)(pter;q11.2). The overall incidence of 11% abnormality indicates that routine chromosome analysis of infertile couples in Kuwait should be considered before the planning of intracytoplasmic sperm injection.     

Cell-free and intracellular nucleic acids: new non-invasive biomarkers to explore male infertility

Male infertility is a devastating problem that affects many couples worldwide. However, the molecular mechanisms and causes of idiopathic male infertility remain unclear. Circulating cell-free nucleic acids have an important role in human physiology and emerging evidence suggests that they play a role in male infertility. This review summarizes recent results on cell-free and intracellular nucleic acids in male infertility and discusses their potential use as biomarkers of male infertility in the clinical practice.     

Assisted reproductive technologies in the reproductive management of small ruminants

In modern agriculture, assisted reproductive technologies are being used for out of season oestrus induction, enhancement of reproductive performance and genetic improvement. In addition, they can have substantial contribution in preservation of endangered species or breeds, as well as in eradication programs of various diseases. While their applications are widespread in cattle, in small ruminants it is almost restricted to artificial insemination. The main limitations of a wider application in small ruminants are the naturally occurring anoestrus period, the variability of response to superovulatory treatments, the fertilisation failure and the need of surgery for collection and transfer of gametes and embryos. Nonetheless, during the last 30 years, considerable progress has been made in sheep and goat embryo technologies, especially in the fields of oestrus synchronisation, superovulation and in vitro embryo production. This paper reviews the status of assisted reproductive technologies in sheep, analysing the prospects offered by recent advances in in vivo and in vitro embryo production from mature and juvenile lambs.     

Effects of male removal on the behaviour and reproductive success of female Eastern Bluebirds Sialia sialis

We removed male Eastern Bluebirds Sialia sialis to examine the importance of male parental care and the behavioural responses of unaided females to loss of male assistance. Unaided females fed young significantly more than control females (females with male assistance) fed young, but young in experimental nests were fed significantly less frequently in total than young in control nests. Unaided females had significantly lower nesting success (fledged at least one young) than control females. At control nests, males defended the young more strongly than did their mates. Unaided females defended their young as strongly as control females. Unaided and control females spent the same amount of time brooding young, and there was no tradeoff between feeding and brooding young. Most early season experimental nests failed, but late in the season many unaided females were as successful as pairs. Unaided females were able to match the feeding rat'e in control broods at late nests but not at early nests, where control nestlings were fed at a higher rate. In our population, male bluebirds played an important role in provisioning young, and early in the season unaided females were unable to provide sufficient bod to raise any young to fledging.     

Anopheles culicifacies: effects of age on the male reproductive system and mating ability of virgin adult mosquitoes

Abstract. Under controlled laboratory conditions of 28–30^oC and 16:8 L:D photoperiod, an attempt was made to develop an age-grading technique for Anopheles culicifacies males. Mating activity was maximal when females were 5–12 days old and males were 5–7 days old. The numbers of total and mature spermatocysts declined significantly with age, and the proportion of the testes occupied by the sperm reservoir increased as virgin males grew older. Mating resulted in the loss of spermatozoa and accessory gland substance from the reproductive system. Loss of mating ability of older virgin males seemed to be age-related, because the reproductive system contained ample supplies of accessory gland substance and spermatozoa. Morphological changes of the reproductive system, due to mating and age, were used to infer the age and reproductive history of unknown males in a laboratory evaluation.     

Medical and socio-cultural aspects of infertility in the Middle East

³ Correspondence address: E-mail: giserour{at}thewayout.net The Middle East (ME), an area rich in history and traditionwith >300 million population, includes 18 heterogeneous countriesconcerning resources, income per capita, available healthcareservices, population density, growth rate, birth rate, totalfertility rate and life expectancy. There is a high prevalenceof infertility in the ME because of post-partum infection, unsafeabortion, iatrogenic tubal and pelvic infertility, tuberculosis,schistosomiasis and high incidence of male factor infertility.It is argued that in the ME, the solution to the problem ofinfertility is its prevention, and population control shouldtake precedence over infertility treatment. However, for a successfulfamily planning program and adoption of small family norms,couples should be reassured that they will be helped to achievepregnancy should they decide so. Prevention and treatment ofinfertility are of particular significance in ME because a womansocial status, her dignity and self-esteem are closely relatedto her ability to have children. Also there is gender sufferingof infertility in the ME. One of the stumbling blocks to acceptanceof assisted reproductive technology (ART) as a line of treatmentof infertility was the unacceptability to the main religiousgroups of the involvement of a third party in the act of procreation.Practices of ART in the ME have many common features and littledifferences. A mechanism had to be found to provide low-costART to the needy.     

New age constraints on the Middle Stone Age occupations of Kharga Oasis, Western Desert, Egypt

Spring-deposited carbonate rocks, or tufas, exposed along the flanks of the Libyan Plateau near Kharga Oasis, Western Desert, Egypt, can provide a directly datable stratigraphic context for Middle Stone Age/Middle Paleolithic (MSA/MP) archaeological material, if such material can be found in situ within tufa strata. Two such localities (Mata'na Site G and Bulaq Wadi 3 Locus 1) described by Caton-Thompson were revisited and sampled for uranium-series analysis. At Mata'na Site G (KH/MT-02), Middle Stone Age ("Upper Levalloisian") material is underlain by tufa with a uranium-series age of 127.9+/-1.3 ka, and overlain by tufa with an age of 103+/-14 ka. At Bulaq Wadi 3 Locus 1, a uranium-series age of 114.4+/-4.2 ka on tufa capping a small collection of Middle Stone Age artifacts also provides a minimum age constraint on that material. Tufa underlying an MSA workshop (KH/MD-10) indicates that this assemblage, characterized by use of several Levallois reduction methods, was deposited after approximately 124 ka. Furthermore, uranium-series ages averaging approximately 133 ka on a Wadi Midauwara tufa (WME-10) without associated archaeological material suggest that one period of spring flow in the region began during the Marine Isotope Stage 6/5e transition, prior to the warmest portion of the last interglacial period. The dated archaeological material suggests that the distinction that has been identified between Nubian and non-Nubian complexes in the Nile Valley may hold for the Western Desert, although local complexity has yet to be fully described.     

Rethinking in vitro embryo culture: new developments in culture platforms and potential to improve assisted reproductive technologies

The preponderance of research toward improving embryo development in vitro has focused on manipulation of the chemical soluble environment, including altering basic salt composition, energy substrate concentration, amino acid makeup, and the effect of various growth factors or addition or subtraction of other supplements. In contrast, relatively little work has been done examining the physical requirements of preimplantation embryos and the role culture platforms or devices can play in influencing embryo development within the laboratory. The goal of this review is not to reevaluate the soluble composition of past and current embryo culture media, but rather to consider how other controlled and precise factors such as time, space, mechanical interactions, gradient diffusions, cell movement, and surface interactions might influence embryo development. Novel culture platforms are being developed as a result of interdisciplinary collaborations between biologists and biomedical, material, chemical, and mechanical engineers. These approaches are looking beyond the soluble media composition and examining issues such as media volume and embryo spacing. Furthermore, methods that permit precise and regulated dynamic embryo culture with fluid flow and embryo movement are now available, and novel culture surfaces are being developed and tested. While several factors remain to be investigated to optimize the efficiency of embryo production, manipulation of the embryo culture microenvironment through novel devices and platforms may offer a pathway toward improving embryo development within the laboratory of the future.     

Carbohydrate metabolism and the temporal occurrence of a serotonin-like indole in the male and female reproductive tract and its relationship with PGF and infertility: a review

Both in the male and in the female reproductive tract glucose can be converted via either the pentose pathway or the sorbitol pathway. It is shown that a disturbed carbohydrate metabolism can lead to infertility, i.e. in the cow and in the bull semen. Evidence is provided that the serotonin-like indole which occurs in the protein-complex and is liberated, can exert effects on the uterine endometrium comparable to those caused by serotonin. It is suggested that the indole liberated can cause ischaemia, followed by regression of the endometrium. When this occurs in repeat breeder cows, exogenous PGF given in mid-cycle on a suitable day, may restore the endometrium so that the cow can again become pregnant. The possibility is mentioned that in humans the free indole might cause regression of the endometrium and some distress symptoms, but thereafter endogenous PGF does increase the vascular permeability resulting finally in bleeding.     

The relative influence of age and weight on the reproductive behaviour of male grey seals Halichoerus grypus

The breeding behaviour of male grey seals Halichoerus grypus of known age and weight was studied on Sable Island, Nova Scotia. Branded males ranged in age from 8 to 16 years and although there was a positive relationship between age and weight, there was a large overlap between age classes. In general, there was an increase in length of tenure and rates of copulation with increasing male age but this was less marked among males between the ages of 13 and 16 years. Compared to older ones, males of 8 and 12 years were observed at more sites, travelled more extensively around the breeding colony, were transient more frequently and were unable to lie as close to females. There was no correlation between male body weight and either length of tenure or rates of copulation when males of age 8 (the smallest males) were excluded from the analysis. Most agonistic behaviour was made by larger, older males towards smaller, younger ones and appeared to be responsible for the short length of tenure and low reproductive rates of young bulls.     

Beyond lifetime reproductive success: the posthumous reproductive dynamics of male Trinidadian guppies

In semelparous populations, dormant germ banks (e.g. seeds) have been proposed as important in maintaining genotypes that are adaptive at different times in fluctuating environments. Such hidden storage of genetic diversity need not be exclusive to dormant banks. Genotype diversity may be preserved in many iteroparous animals through sperm-storage mechanisms in females. This allows males to reproduce posthumously and increase the effective sizes of seemingly female-biased populations. Although long-term sperm storage has been demonstrated in many organisms, the understanding of its importance in the wild is very poor. We here show the prevalence of male posthumous reproduction in wild Trinidadian guppies, through the combination of mark–recapture and pedigree analyses of a multigenerational individual-based dataset. A significant proportion of the reproductive population consisted of dead males, who could conceive up to 10 months after death (the maximum allowed by the length of the dataset), which is more than twice the estimated generation time. Demographic analysis shows that the fecundity of dead males can play an important role in population growth and selection.     

Cryobanking mammalian embryos: Priorities and the optimal choice of reproductive technologies

This article reviews the main achievements in embryo cryobanking in conservation and preservation of animal strains, breeds, and species. Modern advances in this technology with respect to the main groups of laboratory and farm animals are discussed. Alternative approaches to solving the problems associated with cryobanking are considered and the priorities are substantiated. Special attention is given to discussing the role of cryobanks and respective reproductive technologies in programs aimed at conservation of genetic resources of wild and endangered mammalian species.     

Affordable assisted reproductive technologies in developing countries: pros and cons

¹ Correspondence address. E-mail: akandewole{at}yahoo.com Infertility in developing countries is pervasive and a seriousconcern. In addition to the personal grief and suffering itcauses, the inability to have children especially in poor communitiescan create broader problems, particularly for the woman. Infertilityservices in developing countries span the spectrum from preventionto treatment. From a societal and public health standpoint,prevention is cost–effective and is considered by manygovernments and public health care providers to be a priorityfor service delivery. While prevention remains paramount, takenalone it ignores the plight of infertile couples, includingthose with non-infectious causes of infertility. Two key argumentsare frequently used to challenge the development of new reproductivetechnologies in developing countries: overpopulation and limitedresources. Evidence supports the conclusion that there is acompelling need for infertility treatment beyond prevention.In many instances, assisted reproductive technologies (ART)are the last hope or the only means to achieve a child for couples.In an effort to make much needed ART to developing countriesaccessible and affordable, developing countries should lookto public–private partnerships. Governments have a responsibilityto ensure safe and effective services including the controlof standards for clinical procedures and the regulation of professionalpractice.