Searchable abstracts of presentations at key conferences on reproductive biology and medicine

ra0003o018 | SRF Student Prize Session | SRF2016

FACS-sorted putative oogonial stem cells from the mouse ovary are neither DDX4-positive nor germ cells

Zarate-Garcia Larissa , Lane Simon I. R. , Merriman Julie A. , Jones Keith T.

Whether the adult mammalian ovary contains oogonial stem cells (OSCs) is controversial. They have been isolated by fluorescence-activated cell sorting (FACS) using the germline marker DEAD box polypeptide 4 (DDX4), previously assumed to be cytoplasmic, not surface-bound. Furthermore their stem cell and germ cell characteristics remain disputed. We applied a validated protocol to isolate mouse putative OSCs from whole ovarian cell suspensions, then assessed their in vitro</...

ra0003o004 | Oral Communications 1: Ovary | SRF2016

Oocyte maturation arrest in endometriosis is caused by elevated levels of Reactive Oxygen Species and enforced via a DNA Damage Response and the Spindle Assembly Checkpoint pathway

Hamdan Mukhri , Jones Keith , Cheong Ying , Lane Simon

Introduction: It has recently been demonstrated that mouse oocytes respond to DNA damage by arresting in Meiosis I. This arrest has been shown to require the activity of the Spindle Assembly Checkpoint (SAC) and the DNA Damage Response (DDR). Given oocytes lack the equivalent of a G2/M checkpoint for DNA damage, the SAC response may be critical to defend against formation of DNA damaged embryos. It is currently unknown whether the DDR SAC pathway is sensitive to physiological ...

ra0001s029 | Control of meiosis | WCRB2014

Major causes of age-related chromosome segregation errors at meiosis I in oocytes

Kitajima Tomoya S

Chromosomes must be properly segregated during meiosis to transmit the correct set of the parental genome into gametes. Incorrect chromosome segregation produces aneuploid gametes, fertilization of which results in pregnancy loss and congenital diseases such as Down syndrome. However, it is known that the frequency incorrect chromosome segregation is extremely high at meiosis I in oocytes (20–40% in humans), compared to other cell divisions. Moreover, the frequency of the...

ra0001p041 | (1) | WCRB2014

Plk1 plays a role in cortical actin polymerisation during meiosis I

Yuen Wai Shan , Zhang Qing-Hua , Carroll John

Female meiosis involves a highly asymmetrical division to form a large secondary oocyte and a small polar body. Polo-like kinase I (Plk1) is a serine/threonine kinase which is highly conserved from yeast to human and is a potent regulator of mitosis including cytokinesis. Plk1 is known to regulate myosin via the activation of RhoA which leads to the contraction of the cleavage furrow in mitotic cells. Indirect evidence has also shown that Plk1 may regulate Cdc42 activity throu...

ra0003p029 | (1) | SRF2016

Membrane potential contributes to generation of high amplitude [Ca2+]i oscillations and sperm behaviour in human spermatozoa

Nitao Elis , Publicover Stephen

Ca2+ signaling is crucial for regulation of sperm motility and [Ca2+]i oscillations may underlie ‘switching’ of sperm behaviors in human spermatozoa, which is believed to be important for sperm progression in the female tract. We have investigated the contribution of membrane potential (Vm) and the sperm Ca2+ channel CatSper to [Ca2+]i oscillations induced by progesterone (P4). Manipulation of Vm was p...

ra0002p016 | (1) | SRF2015

Membrane potential is crucial for one of the [Ca2+]i oscillations profiles induced by progesterone in human spermatozoa

Nitao Elis Torrezan Goncalves Ramalho , Publicover Stephen J

Ca2+ signalling is critical for regulation of sperm motility. [Ca2+]i oscillations, which may underlie observed ‘switching’ of sperm behaviors, occur in human spermatozoa stimulated with progesterone. Our work aimed to investigate the potential contribution of changes in membrane potential, leading to cyclical activation of voltage dependent Ca2+-influx pathways, to [Ca2+]i oscillations. Spermatozoa we...

ra0001s003 | Epigenetic reprogramming in reproduction | WCRB2014

The origin and fate of epimutations in offspring produced by assisted reproductive technologies

McCarrey John R

Epimutations are heritable defects in epigenetic programming that do not involve changes in the underlying DNA sequence and may or may not impact gene expression. Epimutations can occur naturally, but are more likely to be induced by environmental factors that disrupt the normal epigenome. Previous studies have shown that the use of assisted reproductive technologies (ART) can induce epimutations in the offspring produced. We chronicled the occurrence of epimtuations in mice p...

ra0002o026 | Oral Communications 4: Female reproduction | SRF2015

Neuroendocrine control of ovulation in primates: a role for two distinct populations of GnRH neurons?

Urbanski Henryk F , Loza Alejandra Marquez , Brown Donald I

GnRH neurons represent the primary neuroendocrine link between the brain and the rest of the reproductive system, and traditionally it has been assumed that a single population of GnRH neurons controls both pusatile LH release as well as the preovulatory LH surge. This view has profoundly influenced our strategies for contraception and for the treatment of infertility in women. Recent data from our laboratory, however, questions the validity of this fundamental assumption. Usi...

ra0003o014 | SRF Post-Doctoral Prize Session | SRF2016

Etoposide results in follicle loss in the fetal mouse ovary, but does not block the ability of oocytes to progress through prophase I of meiosis

Stefansdottir Agnes , Johnston Zoe , Powles-Glover Nicola , Anderson Richard , Adams Ian , Spears Norah

Introduction: The chemotherapy agent etoposide is a topoisomerase II (topo II) inhibitor, and is considered safe to administer during pregnancy. However, assessment of its effects on the developing ovary, when germ cells are undergoing initiation of meiosis and forming follicles, has been limited. We have investigated this using ovarian tissue culture.Methods: E13.5 mouse ovaries were cultured for 12 days on an agar block, with etoposide added for the fi...

ra0001p210 | (1) | WCRB2014

Proteomic analysis of human testicular interstitial fluid reflects disordered spermatogenesis in Klinefelter’s syndrome

McLachlan Robert I , Stephens Andrew N , Rainczuk Adam , Foo Caroline , Condina Mark R , Ishikawa Tomomoto , Weidner Wolfgang , Stanton Peter G

Introduction: Primary spermatogenic failure is the commonest cause of male infertility. Changes in Sertoli and germ cell function may be reflected in the testicular interstitial fluid (TIF) proteome and its analysis may provide insights into the pathophysiology. Microdissection testicular sperm extraction (microTESE) provides sperm for ICSI in ~50% of non-obstructive azoospermia (NOA) cases. As the first step in constructing a diagnostic approach for broader application in NOA...