LAUSR

As much as we have learned about the intratesticular, extratesticular, and intrauterine lifespan of human sperm, sorting out those capable of enacting the first steps in human development remains a major challenge in ARTs. From their very beginnings as stem cells transformed into primary spermatocytes (see issue cover), these highly differentiated cells stored in the epididymis assume an identity and character conducive to fertilization and egg activation only after receiving an appropriate set of cues from the environments they transit. While the cargo transmitted by sperm to the nascent zygote is being clarified as an ever-growing list of long sought consumables (see below), putting the male gamete on equal footing with that of the female has for years spawned a debate extending well back into the sixteenth century. Think Homunculus. In her scholarly work of 1997, Clara PintoCorreira (The Ovary of Eve: Egg and Sperm and Preformation, ISBN 0-226-66952-1, University of Chicago Press) traces the tortuous debate that raged in the quest for understanding the very roots of embryology when (real data aside) the guesswork of the spermists and ovists sought truth to their respective claims of life having its origins in one but not the other of sexes. In its various iterations, the battle of the sexes continues today as reproductive medicine uneasily basks in a scholarly medium rich in molecular and mechanistic detail comparable to the legendary battle waged in the 1970s between Billie Jean King and the late Bobby Riggs. Bragging rights aside, until recently the ovists have dominated the gamete landscape in the arena of human ARTs, much as it became appreciated in yesteryear upon the advent of microscopy—when seeing became believing. With this back drop, we deliver our readership a series of articles highlighting in a tempered and tempting fashion of some of the issues arising from a more spermatocentric orientation. From understanding and managing the risks associated with sperm-borne viral transmission, Dubaut and colleagues provide a timely update on Zika infections (Impact of Zika virus for infertility specialists: current literature, guidelines, and resources https://doi.org/10.1007/s10815-017-0988) through to new and old genetic discoveries that are adding to our understanding of the multidimensional nature of male fertility and infertility (The − 29G/A FSH receptor gene polymorphism is associated with higher FSH and LH levels in normozoospermic men https://doi.org/10.1007/s10815017-0970; Detection of candidate nectin gene mutations in infertile men with severe teratospermia https://doi.org/10. 1007/s10815-017-0985-4). In practical terms, the introduction and application of cryopreservation to ARTs were milestones initially staged for animal semen and readily translated into sperm banking for humans, paving the way for the Blay away^ mentality that is so pervasive and prominent in reproductive medicine. Towards this end, Palomar Rios and colleagues draw attention to some of the limitations of sperm cryopreservation as we know them today and suggest directions for future improvements likely to make a difference in fertility preservation strategies for men (Sperm parameters that play a major role in the assessment of semen quality after cryopreservation https://doi. org/10.1007/s10815-017-0973-8). And teasing apart causes of male infertility relative to other conditions such as metabolic syndrome has proven to be a serious challenge warranting the search for alternative biomarkers of male reproductive health (Serum microRNAs in male subfertility—biomarkers * David F. Albertini [email protected]