Liza O'Donnell's research while affiliated with The University of Newcastle, Australia and other places

Publications (98)

Article
Full-text available
Glucocorticoids are steroids involved in key physiological processes such as development, metabolism, inflammatory and stress responses and are mostly used exogenously as medications to treat various inflammation-based conditions. They act via the glucocorticoid receptor (GR) expressed in most cells. Exogenous glucocorticoids can negatively impact...
Article
Spermatozoa are comprised of many unique proteins not expressed elsewhere. Sperm-specific proteins are first expressed at puberty, after the development of immune tolerance to self-antigens, and have been assumed to remain confined inside the seminiferous tubules, protected from immune cell recognition by various mechanisms of testicular immune pri...
Article
Full-text available
The long-standing knowledge that Sertoli cells determine fetal testosterone production levels is not widespread, despite being first reported over a decade ago in studies of mice. Hence any ongoing use of testosterone as a marker of Leydig cell function in fetal testes is inappropriate. By interrogating new scRNAseq data from human fetal testes, we...
Article
Testicular Leydig cells (LCs) are the principal source of circulating testosterone in males. LC steroidogenesis maintains sexual function, fertility and general health, and is influenced by various paracrine factors. The leukemia inhibitory factor receptor (LIFR) is expressed in the testis and activated by different ligands, including leukemia inhi...
Article
Sertoli cells are the orchestrators of spermatogenesis; they support fetal germ cell commitment to the male pathway and are essential for germ cell development, from maintenance of the spermatogonial stem cell niche and spermatogonial populations, through meiosis and spermiogeneis and to the final release of mature spermatids during spermiation. Ho...
Article
Activin A promotes fetal mouse testis development, including by driving Sertoli cell proliferation and cord morphogenesis, but its mechanisms of action are undefined. We performed RNA-seq on testicular somatic cells from fetal activin A-deficient mice (Inhba KO) and wildtype littermates at embryonic ages E13.5 and E15.5. Analysis of whole gonads pr...
Article
As germ cells progress through spermatogenesis, they undergo a dramatic transformation, wherein a single, diploid spermatogonial stem cell ultimately produces thousands of highly specialised, haploid spermatozoa. The cytoskeleton is an integral aspect of all eukaryotic cells. It concomitantly provides both structural support and functional pliabili...
Data
KATNAL2 is not essential for cell cycle progression. (a) Germ cell apoptosis in Katnal2Y86C/Y86C mice. The average number of germ cells per seminiferous tubules positive for either cleaved-caspase 3 or cleaved-caspase 9 showed no difference between Katnal2WT/WT and Katnal2Y86C/Y86C mice (n = 3/genotype). Lines represent mean ± SD. (b) KATNAL2 overe...
Data
Primer sequences for SYBR Green qPCR. (DOCX)
Data
Primer sequences for mouse genotyping. (DOCX)
Data
Validation of immunolabelling specificity. The specificity of immunolabelling as shown by the staining of parallel samples in the absence of primary antibody. α-tubulin (a) and acetylated tubulin (b) testis immunohistochemistry and corresponding primary antibody negative controls. (c) Centrin immunolabelling (red) on isolated germ cells and corresp...
Data
Manchette structure in Katnal2Y86C/Y86C mice. α-tubulin immunolabelling (green) as a marker for manchettes in Katnal2WT/WT and Katnal2Y86C/Y86C isolated spermatids. Elongating spermatids are shown in progressive steps of manchette development and spermatid elongation from left to right. Cells were counterstained with DAPI (blue) to visualize DNA. S...
Data
Efficiency of Katnal2 exon 3 excision in Katnal2 GCKO mice. qPCR analysis of Katnal2 transcript levels in isolated round spermatids from Katnal2GCKO/GCKO mice relative to Katnal2FLOX/FLOX (n = 3/genotype). Katnal2 transcript levels in isolated round spermatids were reduced by 99.9% in Katnal2GCKO/GCKO mice compared to Katnal2FLOX/FLOX mice. Lines r...
Data
Spermatogenic defects in Katnal2KO/KO mice. (a). The Katnal2 knockout first, conditional-ready allele. The FRT-LacZ-loxP-Neo-FRT-loxP-Katnal2-exon3-loxP cassette was inserted into intron 2 of the Katnal2 gene. (b) Testis weight in Katnal2WT/WT (white triangles; n = 5) and Katnal2KO/KO (black triangles; n = 6) mice. (c) Daily sperm output (DSP) in t...
Data
Validation of the KATNAL2 antibody. Immunochemistry of KATNAL2 in Katnal2WT/WT and Katnal2KO/KO testis sections confirmed the specificity of the KATNAL2 antibody. Green represents KATNAL2 and blue represents DNA as labeled by DAPI. Scale bars = 10 μm. (TIF)
Article
Full-text available
Author summary Male infertility affects one in twenty men of reproductive age in western countries. Despite this, the biochemical basis of common defects, including reduced sperm count and abnormal sperm structure and function, remains poorly defined. Microtubules are cellular “scaffolds” that serve critical roles in all cells, including developing...
Data
Assessment and validation of the KATNAL2Y86C mutation. (a–b) KATNAL2 protein expression in whole testis homogenates of Katnal2Y86C/Y86C mice. (a) Western blot analysis of KATNAL2 protein expression in whole adult testis homogenates from Katnal2WT/WT and Katnal2Y86C/Y86C mice. (b) Densitometry of the western blot analysis of the 46 kDa KATNAL2 isofo...
Data
Validation of in situ proximity ligation assay specificity. The specificity of the in situ proximity ligation assays as shown by the staining of parallel samples in the absence of either both or one of the primary antibodies. In situ proximity ligation assays using antibodies directed against KATNB1 and KATNAL2 (a), TUBD1 and KATNAL2 (b), and TUBE1...
Article
Communication between the testicular somatic- (Sertoli, Leydig, peritubular myoid, macrophage) and germ- cell types is essential for sperm production (spermatogenesis), but the communicating factors are poorly understood. We reasoned that identification of proteins in the testicular interstitial fluid (TIF) that bathes these cells could provide a n...
Chapter
Androgen and estrogen signalling act as key controllers of Sertoli cell regulation of spermatogenesis. This chapter describes how research in the past decade has significantly advanced our understanding of how the sex hormones influence Sertoli cell development and adult function. We describe the role of androgens in attaining a full complement of...
Article
Haploid round spermatids undergo a remarkable transformation during spermiogenesis. The nucleus polarizes to one side of the cell as the nucleus condenses and elongates, and the microtubule-based manchette sculpts the nucleus into its species-specific head shape. The assembly of the central component of the sperm flagellum, known as the axoneme, be...
Article
Full-text available
Male infertility affects at least 5% of reproductive age males. The most common pathology is a complex presentation of decreased sperm output and abnormal sperm shape and motility referred to as oligoasthenoteratospermia (OAT). For the majority of OAT men a precise diagnosis cannot be provided. Here we demonstrate that leucine-rich repeats and guan...
Article
Male germ cell genome integrity is critical for spermatogenesis, fertility and normal development of the offspring. Several DNA repair pathways exist in male germ cells. One such important pathway is the Fanconi anemia (FANC) pathway. Unlike in somatic cells, expression profiles and the role of the FANC pathway in germ cells remain largely unknown....
Article
Oligoasthenoteratozoospermia (OAT) is a phenotype frequently observed in infertile men, and is defined by low spermatozoa number, abnormal spermatozoa morphology and poor motility. We previously showed that a mutation in the Katnb1 gene in mice causes infertility because of OAT. The KATNB1 gene encodes an accessory subunit of the katanin microtubul...
Article
Microtubules are dynamic polymers of tubulin subunits that underpin many essential cellular processes, such as cell division and migration. Spermatogenesis is the process by which spermatogenic stem cells undergo mitotic and meiotic division and differentiation to produce streamlined spermatozoa capable of motility and fertilization. This review su...
Data
RBM5 interacting proteins in round spermatids identified using immunoprecipitation and mass spectrometry analysis. (DOC)
Data
Primers used for genotyping and RT-PCR analysis. (DOCX)
Article
Full-text available
Alternative splicing of precursor messenger RNA (pre-mRNA) is common in mammalian cells and enables the production of multiple gene products from a single gene, thus increasing transcriptome and proteome diversity. Disturbance of splicing regulation is associated with many human diseases; however, key splicing factors that control tissue-specific a...
Article
This chapter describes the approach to define the cause of male infertility in a genetically modified male mouse. It provides a guide to the establishment of the infertility status and whether it is due to the failure of mating or due to abnormalities of the sperm output, motility, and morphology. Further assessments define the nature of the sperma...
Data
Bioinformatic analysis of androgen-responsive proteins in enriched meiotic cell preparations. (XLS)
Data
Differentially Expressed Proteins Identified by MALDI-TOF MS+MS/MS, PMF/MALDI, LCMS/MS Scaffold and LCMS/MS; detailed mass spectrometry data. (XLS)
Article
Full-text available
The production of mature sperm is reliant on androgen action within the testis, and it is well established that androgens act on receptors within the somatic Sertoli cells to stimulate male germ cell development. Mice lacking Sertoli cell androgen receptors (AR) show late meiotic germ cell arrest, suggesting Sertoli cells transduce the androgenic s...
Data
Full-text available
Mass spectra for identified proteins. (PDF)
Data
Differentially expressed proteins in meiotic cell preparations. (XLS)
Article
Testosterone production and action is critical for male fertility. An absence of androgen signaling during fetal life results in failure of the urogenital tract to virilize, inhibition of testicular descent, abnormalities in accessory organs, such as the epididymis, prostate and seminal vesicles, and an inability to produce sperm. This chapter focu...
Data
Stereological analysis of spermatogenesis in Katnb1WT/WT (WT) and Katnb1Taily/Taily (Taily) mice. a Data expressed as mean±SEM. * denotes p<0.05 compared to wildtype (WT) using unpaired t test. b Early spermatocytes include preleptotene to pachytene spermatocytes in stage VIII. c Late spermatocytes include pachytene and diplotene spermatocytes in s...
Data
3D imaging of spermatid manchettes in Katnb1Taily/Taily mice. Spermatids were isolated from Katnb1Taily/Taily mice and immunostained for microtubules to visualize the manchette. Green = α-tubulin, blue = DNA (TOPRO). (AVI)
Data
3D imaging of spermatid manchettes in Katnb1WT/WT mice. Spermatids were isolated from Katnb1WT/WT mice and immunostained for microtubules to visualize the manchette. Green = α-tubulin, blue = DNA (TOPRO). (AVI)
Data
Antibodies and detection methodologies for immunohistochemical analysis. A summary of the suppliers, concentrations used and detection methodology for each primary antibody used for immunohistochemical analysis within the study. (DOCX)
Data
3D imaging of p60 katanin in meiotic spindles in Katnb1WT/WT mice. Red = katanin p60, green = α-tubulin, blue = DNA (DAPI). (AVI)
Data
Full-text available
Immunolocalization of katanin p60 (red) to microtubules of meiotic midbodies (arrows) in Katnb1WT/WT and Katnb1Taily/Taily mice. Green = α-tubulin (microtubules, MTs), blue = DNA (DAPI). (PDF)
Data
Full-text available
Diagram of the microtubule-based manchette in spermatids. The spermatid acrosome overlying the nucleus associates, via a specialized adhesion junction, with F-actin-containing “hoops” in the Sertoli cell cytoplasm. Beneath the acrosome is the acroplaxome and the closely associated perinuclear ring, from which the manchette microtubules are believed...
Data
Validation of a custom KATNAL1 antibody. The efficacy of the custom-designed KATNAL1 antibody was confirmed via dual-colour fluorescent Western blotting on whole-testis lysate. This identified a single, specific band corresponding to KATNAL1. An antibody against β-actin labelled with a different fluorophore was included as a loading-control antibod...
Data
Full-text available
Phylogeny of selected representatives of RAB subfamilies in comparison to likely RABL2 orthologues. Numbers on internodes refer to MrBayes posterior probability/PhyML bootstrap support values and the PhyML topology is shown. RABL2 species included are as follows: Homo sapiens (RABL2A and RABL2B), Mus musculus, Trypanosoma brucei, and Chlamydomonas...
Data
Body weight (g) in Katnb1WT/WT (WT, n = 13) and Katnb1Taily/Taily (Mutant, n = 21) mice. No significant differences were observed. (PDF)
Data
3D imaging of p60 katanin in meiotic spindles in Katnb1Taily/Taily mice. Red = katanin p60, green = α-tubulin, blue = DNA (DAPI). (AVI)
Article
Full-text available
Spermatogenesis is a complex process reliant upon interactions between germ cells (GC) and supporting somatic cells. Testicular Sertoli cells (SC) support GCs during maturation through physical attachment, the provision of nutrients, and protection from immunological attack. This role is facilitated by an active cytoskeleton of parallel microtubule...
Article
Full-text available
Katanin is an evolutionarily conserved microtubule-severing complex implicated in multiple aspects of microtubule dynamics. Katanin consists of a p60 severing enzyme and a p80 regulatory subunit. The p80 subunit is thought to regulate complex targeting and severing activity, but its precise role remains elusive. In lower-order species, the katanin...
Conference Paper
http://www.biolreprod.org/cgi/content/meeting_abstract/85/1_MeetingAbstracts/62
Article
Spermatogenesis is absolutely dependent on follicle stimulating hormone (FSH) and androgens; acute suppression of these hormones inhibits germ cell development and thus sperm production. The removal of intercellular junctions and release of spermatids by the Sertoli cell, a process known as spermiation, is particularly sensitive to acute hormone su...
Article
Full-text available
Spermiation is the process by which mature spermatids are released from Sertoli cells into the seminiferous tubule lumen prior to their passage to the epididymis. It takes place over several days at the apical edge of the seminiferous epithelium, and involves several discrete steps including remodelling of the spermatid head and cytoplasm, removal...
Article
Full-text available
Spermatogenesis is absolutely dependent on FSH and androgens; suppression of these hormones inhibits germ cell development and thus sperm production. The final release of spermatids by the Sertoli cell, a process known as spermiation, is particularly sensitive to hormone suppression. To define the molecular mechanisms that mediate FSH and androgen...
Article
Spermatogenesis is absolutely dependent on follicle stimulating hormone (FSH) and androgens; acute suppression of these hormones inhibits germ cell development and thus sperm production. The removal of intercellular junctions and release of spermatids by the Sertoli cell, a process known as spermiation, is particularly sensitive to acute hormone su...
Article
Spermatogenesis occurs within the highly complex seminiferous epithelium. This cyclic process is accompanied by dynamic stage-specific transcriptional changes and is driven by androgens and FSH by mechanisms that are unclear. Here we report the impact of acute androgen and FSH suppression on the transcriptional dynamics of the seminiferous epitheli...
Article
Acute suppression of circulating reproductive hormones (FSH and testosterone) inhibits sperm release (spermiation) (1), although the molecular mechanisms of spermiation failure are poorly understood. Micro-RNAs (miRNAs) are small non-coding RNAs that regulate protein expression, and are essential for normal spermatogenesis. Recent studies suggest t...
Article
The isolation and molecular analysis of highly purified cell populations from complex, heterogeneous tissues has been a challenge for many years. Spermatogenesis in the testis is a particularly difficult process to study given the unique multiple cellular associations within the seminiferous epithelium, making the isolation of specific cell types d...
Article
Full-text available
Spermiation is the final step of spermatogenesis and culminates in the disengagement (release) of elongated spermatids from Sertoli cells into the seminiferous tubule lumen. Spermiation failure, wherein spermatids are retained by Sertoli cells instead of releasing, occurs after hormone suppression. The mechanisms involved in spermatid disengagement...
Article
Full-text available
Male hormonal contraception via gonadotropin and intratesticular androgen withdrawal disrupts spermatogenesis at two principal sites: 1) spermatogonial maturation, and 2) spermiation. The objective of this study was to explore the relative dependence of each stage of germ cell development on FSH and LH/intratesticular androgen action. Eighteen men...
Article
Spermatogenesis is dependent on the ability of Sertoli cells to form mature junctions that maintain a unique environment within the seminiferous epithelium. Adjacent Sertoli cells form a junctional complex that includes classical adherens junctions and testis-specific ectoplasmic specialisations (ES). The regulation of inter-Sertoli cell junctions...
Article
Full-text available
Combination of a GnRH antagonist (acyline), types I and II, 5alpha-reductase inhibitor (dutasteride) or levonorgestrel (LNG) with testosterone (T) treatment may augment the suppression of spermatogenesis and intratesticular (iT) steroids. The objective of this study was to assess the effects of combined hormonal contraceptive regimens on germ cell...
Article
To quantify germ cell loss and the extent of testicular fibrosis in vasectomized patients of varying obstructive intervals. Retrospective study. Specialized male reproductive surgery and endocrinology service. Thirty-four vasectomized patients 1-20 years after surgery and 10 normal subjects. Thirty-four testicular biopsies taken at the time of vase...
Article
The pubertal initiation of spermatogenesis is reliant on androgens, and during this time, 5alpha-reduced androgens such as dihydrotestosterone (DHT) are the predominant androgens in the testis. Two 5alpha-reductase (5alphaR) isoenzymes (5alphaR1 and 5alphaR2) have been identified, which catalyze the conversion of testosterone to the more potent and...
Article
At the end of spermatogenesis, elongated spermatids are released from supporting Sertoli cells via the process termed spermiation. Previous studies have shown that spermiation failure occurs after hormone suppression, in which spermatids are retained instead of releasing. However, the molecular mechanisms involved in spermiation and spermiation fai...
Article
Full-text available
Testosterone is metabolised to the more potent androgen, dihydrotestosterone, by the 5alpha-reductase (5alphaR) enzyme. We previously showed that 5alpha-reduced androgens are important for maintaining androgen action on rat spermatogenesis when testicular testosterone concentrations are reduced. This study investigated expression and activity of th...
Article
Steroids play a critical role in gonadal differentiation in birds, reptiles, and amphibia whereas gonadal differentiation in mammals is thought to be determined by genetic mechanisms. The gonads of female mice incapable of synthesizing estrogens due to disruption of the aromatase gene (ArKO) provide a unique model to test the role of estrogen in re...
Article
Spermatogenesis in the rat consists of 14 unique morphologic cellular associations between Sertoli cells and developing germ cells within the seminiferous epithelium. The complexity of the cellular associations leads to difficulty in the isolation of individual cells at a defined stage of development for the study of their unique patterns of gene o...
Article
Estrogen is synthesized in the testis, both in Leydig cells and seminiferous epithelium, and its importance in spermatogenesis is highlighted by the phenotype of the aromatase knockout (ArKO) mouse. These mice are unable to synthesize endogenous estrogens. The males develop postmeiotic defects by 18 wk of age. We hypothesized that maintenance of sp...
Article
Sex steroid-based male contraceptive regimens do not induce consistent azoospermia. The reason for this variable response is obscure. We used normal adult male monkeys, Macaca fascicularis (n = 9) as a model of testosterone (T)-induced gonadotropin suppression to understand the basis for variability in spermatogenic suppression during hormonal cont...
Article
Sex steroid-based male contraceptive regimens do not induce consistent azoospermia. The reason for this variable response is obscure. We used normal adult male monkeys, Macaca fascicularis (n = 9) as a model of testosterone (T)-induced gonadotropin suppression to understand the basis for variability in spermatogenic suppression during hormonal cont...
Article
The steroidogenic pathway within the ovary gives rise to progestins, androgens and oestrogens, all of which act via specific nuclear receptors to regulate reproductive function and maintain fertility. The precise role of oestrogen in the ovary remains to be elucidated, hence the data presented here which arises from studies designed to resolve this...
Article
This study investigates the effects of spermatogenic germ cells on inhibin alpha-subunit and beta B-subunit expression, and inhibin alpha-subunit and inhibin B production by rat Sertoli cells in vitro. Sertoli cells isolated from 19-day-old rats were cultured for 48 h at 32 degrees C, in the presence or absence of FSH (2.3-2350 mIU/ml), and in the...
Article
Full-text available
Testosterone (T) treatment suppresses gonadotropin levels and sperm counts in normal men, but the addition of a progestin may improve the efficacy of hormonal contraception. This study aimed to investigate the speed and extent of suppression of testicular germ cell number induced by T plus or minus progestin treatment and correlate these changes wi...
Article
Full-text available
A detailed understanding of the hormonal regulation of spermatogenesis is required for the informed assessment and management of male fertility and, conversely, for the development of safe and reversible male hormonal contraception. An approach to the study of these issues is outlined based on the use of well-defined in vivo models of gonadotropin/...
Article
Although it has been known for many years that estrogen administration has deleterious effects on male fertility, data from transgenic mice deficient in estrogen receptors or aromatase point to an essential physiological role for estrogen in male fertility. This review summarizes the current knowledge on the localization of estrogen receptors and a...
Article
Human male hormonal contraceptive regimens do not consistently induce azoospermia, and the basis of this variable response is unclear. This study used nine adult macaque monkeys (Macaca fascicularis) given testosterone (T) implants for 20 weeks to study changes in germ cell populations in relation to sperm output. Germ cell numbers were determined...
Article
Human male hormonal contraceptive regimens do not consistently induce azoospermia, and the basis of this variable response is unclear. This study used nine adult macaque monkeys (Macaca fascicularis) given testosterone (T) implants for 20 weeks to study changes in germ cell populations in relation to sperm output. Germ cell numbers were determined...
Article
Oestrogens have been known for many years to have a direct influence on folliculogenesis. Oestradiol-17beta (E2) and its analogues have both proliferative and differentiative effects on somatic cells of follicles. Nevertheless, definitive proof of an obligatory role for oestrogen in folliculogenesis and elucidation of the mechanisms subserving its...
Article
The relative abundance and physiological role of 5alpha-reductase (5alphaR) isoforms in rat testis, in particular 5alpha-reductase Type 2 (5alphaR2) are poorly understood. Investigation of 5alphaR2 activity using enzyme kinetic studies was hampered by the high concentrations of 5alpha-reductase Type 1 (5alphaR1) in rat testis. Therefore, an assay w...
Article
Spermiation is the process by which mature sperm are released from the Sertoli cell into the lumen of the seminiferous tubule. Previous studies have shown that FSH and LH/testosterone suppression causes a significant increase in the degeneration of mature elongated spermatids. The purpose of this study was to investigate the extent to which spermia...