RBM46 is essential for gametogenesis and functions in post-transcriptional roles affecting meiotic cohesin subunits

RBM46 is a germ cell-specific RNA-binding protein required for gametogenesis, but the targets and molecular functions of RBM46 remain unknown. Here, we demonstrate that RBM46 binds at specific motifs in the 3'UTRs of mRNAs encoding multiple meiotic cohesin subunits and show that RBM46 is required for normal synaptonemal complex formation during meiosis initiation. Using a recently reported, high-resolution technique known as LACE-seq and working with low-input cells, we profiled the targets of RBM46 at single-nucleotide resolution in leptotene and zygotene stage gametes. We found that RBM46 preferentially binds target mRNAs containing GCCUAU/GUUCGA motifs in their 3'UTRs regions. In Rbm46 knockout mice, the RBM46-target cohesin subunits displayed unaltered mRNA levels but had reduced translation, resulting in the failed assembly of axial elements, synapsis disruption, and meiotic arrest. Our study thus provides mechanistic insights into the molecular functions of RBM46 in gametogenesis and illustrates the power of LACE-seq for investigations of RNA-binding protein functions when working with low-abundance input materials.

Molecular Mechanism of Aurora Kinase A Regulating the Meiosis of Oocyte / 中国医学科学院学报

Aurora kinase A (AURKA),a family member of aurora kinases,is involved in mitotic entry,maturation and separation of centrosome,assembly and stabilization of bipolar spindle,and condensation and separation of chromosome.Studies have demonstrated that AURKA plays a similar role in meiosis,while the specific mechanism and the similarities and differences in its role between meiosis and mitosis remain unclear.Therefore,we reviewed the studies about the localization and activation of AURKA in oocyte meiosis,and compared the role of AURKA in regulating spindle formation,activating spindle assembly checkpoint,and correcting the kinetochore-microtubule attachment between the meiosis of oocytes and the mitosis of somatic cells.This review will lay a theoretical foundation for revealing the mechanism of AURKA in the regulation of cell division and for the clinical research related to cancer and reproduction.

Morphology and Biochemistry of Ovulation Morfologia e bioquímica da ovulação

Abstract The process of ovulation involves multiple and iterrelated genetic, biochemical, and morphological events: cessation of the proliferation of granulosa cells, resumption of oocyte meiosis, expansion of cumulus cell-oocyte complexes, digestion of the follicle wall, and extrusion of the metaphase-II oocyte. The present narrative review examines these interrelated steps in detail. The combined or isolated roles of the folliclestimulating hormone (FSH) and luteinizing hormone (LH) are highlighted. Genes indiced by the FSH genes are relevant in the cumulus expansion, and LH-induced genes are critical for the resumption ofmeiosis and digestion of the follicle wall. A nonhuman model for follicle-wall digestion and oocyte release was provided.

Resumo O processo de ovulação envolve modificações genéticas, bioquímicas e morfológicas múltiplas e interrelacionadas: suspensão da proliferação das células da granulosa, reinício da meiose do oócito, expansão das células do complexo cumulus-oócito, digestão da parede folicular, e extrusão do oócito. Esta revisão narrativa examina em detalhes cada um desses eventos e os principais genes e proteínas envolvidos. Mais importante, a ação combinada ou isolada do hormônio folículo-estimulante (HFE) e do hormônio luteinizante (HL) é destacada. Detalha-se o papel do HFE na expansão do cumulus e do HL na digestão da parede folicular, permitindo a extrusão do oócito na superfície ovariana. Proveu-se um modelo não humano para explicar a digestão da parede folicular.

Research progress of cyclic adenosine monophosphate in mammalian follicular development / 生理学报

Cyclic adenosine monophosphate (cAMP) is one of the significant and conserved second messengers in mammals, and it participates in regulating the developmental and physiological functions of various organs and tissues through transducting extracellular signals. Studies have shown that the process of meiosis in female mammalian oocytes is closely related to the level of cAMP and strictly regulated. In oocytes, cAMP is mainly synthesized by adenylate cyclase 3 (AC3) and degraded by phosphodiesterase 3A (PDE3A), both of which jointly regulate the level of cAMP in oocytes and play important roles in the follicular development and oogenesis of female ovaries. It has been well illuminated that high level of cAMP in the cytoplasm of oocytes in growing follicles could maintain the arrest of the first meiotic of oocytes for a long time. The oocytes will resume meiosis and mature either when the synthesis of cAMP is down-regulated, or when cAMP is degraded by PDE3A. In recent years, the novo physiological functions of cAMP in oogenesis have been reported. To better understand the regulatory role and mechanism of cAMP in mammalian gametogenesis, this paper reviews the relevant research regarding the relationship between cAMP and germ cell development.

Advances in research on the development of female germ cells / 中华医学遗传学杂志

The development of female germ cells can be mainly divided into two stages: fetal germ cells and oocytes in folliculogenesis after puberty. Mitosis-meiosis transition, meiosis arrest and re-activation are the key phases of the development. Several phases may be characterized by their distinct molecular events, which involve precise regulation of gene expression and interaction with corresponding gonadal niche cells. In recent years, single-cell transcriptome studies have clarified phase-specific patterns of gene expression, signaling pathways and epigenetic modification during oogenesis and folliculogenesis. These works have provided important insights into the development of female germ cells and pathogenesis of germ-cell related diseases, which may promote clinical application of reproductive genetic research.

The organization, regulation, and biological functions of the synaptonemal complex / 亚洲男科学杂志(英文版)

The synaptonemal complex (SC) is a meiosis-specific proteinaceous macromolecular structure that assembles between paired homologous chromosomes during meiosis in various eukaryotes. The SC has a highly conserved ultrastructure and plays critical roles in controlling multiple steps in meiotic recombination and crossover formation, ensuring accurate meiotic chromosome segregation. Recent studies in different organisms, facilitated by advances in super-resolution microscopy, have provided insights into the macromolecular structure of the SC, including the internal organization of the meiotic chromosome axis and SC central region, the regulatory pathways that control SC assembly and dynamics, and the biological functions exerted by the SC and its substructures. This review summarizes recent discoveries about how the SC is organized and regulated that help to explain the biological functions associated with this meiosis-specific structure.

The role of retinoic acid in the commitment to meiosis / 亚洲男科学杂志(英文版)

Male meiosis is a complex process whereby spermatocytes undergo cell division to form haploid cells. This review focuses on the role of retinoic acid (RA) in meiosis, as well as several processes regulated by RA before cell entry into meiosis that are critical for proper meiotic entry and completion. Here, we discuss RA metabolism in the testis as well as the roles of stimulated by retinoic acid gene 8 (STRA8) and MEIOSIN, which are responsive to RA and are critical for meiosis. We assert that transcriptional regulation in the spermatogonia is critical for successful meiosis.

The molecular control of meiotic double-strand break (DSB) formation and its significance in human infertility / 亚洲男科学杂志(英文版)

Meiosis is an essential step in gametogenesis which is the key process in sexually reproducing organisms as meiotic aberrations may result in infertility. In meiosis, programmed DNA double-strand break (DSB) formation is one of the fundamental processes that are essential for maintaining homolog interactions and correcting segregation of chromosomes. Although the number and distribution of meiotic DSBs are tightly regulated, still abnormalities in DSB formation are known to cause meiotic arrest and infertility. This review is a detailed account of molecular bases of meiotic DSB formation, its evolutionary conservation, and variations in different species. We further reviewed the mutations of DSB formation genes in association with human infertility and also proposed the future directions and strategies about the study of meiotic DSB formation.

Crossover patterns under meiotic chromosome program / 亚洲男科学杂志(英文版)

Repairing DNA double-strand breaks (DSBs) with homologous chromosomes as templates is the hallmark of meiosis. The critical outcome of meiotic homologous recombination is crossovers, which ensure faithful chromosome segregation and promote genetic diversity of progenies. Crossover patterns are tightly controlled and exhibit three characteristics: obligatory crossover, crossover interference, and crossover homeostasis. Aberrant crossover patterns are the leading cause of infertility, miscarriage, and congenital disease. Crossover recombination occurs in the context of meiotic chromosomes, and it is tightly integrated with and regulated by meiotic chromosome structure both locally and globally. Meiotic chromosomes are organized in a loop-axis architecture. Diverse evidence shows that chromosome axis length determines crossover frequency. Interestingly, short chromosomes show different crossover patterns compared to long chromosomes. A high frequency of human embryos are aneuploid, primarily derived from female meiosis errors. Dramatically increased aneuploidy in older women is the well-known "maternal age effect." However, a high frequency of aneuploidy also occurs in young women, derived from crossover maturation inefficiency in human females. In addition, frequency of human aneuploidy also shows other age-dependent alterations. Here, current advances in the understanding of these issues are reviewed, regulation of crossover patterns by meiotic chromosomes are discussed, and issues that remain to be investigated are suggested.

Advances in molecular mechanisms of meiotic arrest and luteinizing hormone-induced meiotic resumption in oocytes / 生理学报

Mammalian oocytes within Graafian follicles are arrested at prophase I of meiosis. C-type natriuretic peptide (NPPC), secreted by mural granulosa cells (MGCs), maintains oocyte meiotic arrest via binding to its cognate receptor natriuretic peptide receptor 2 (NPR2) and producing cyclic guanosine monophosphate (cGMP). NPR2 is most concentrated in the cumulus cells. In addition, cAMP, gap junction, inosine monophosphate dehydrogenase (IMPDH) and other important regulatory factors are also involved in meiotic arrest. Luteinizing hormone (LH) then rapidly decreases cGMP and induces oocyte meiotic resumption. In this paper, advances in the molecular mechanisms of meiotic arrest and LH-induced meiotic resumption were reviewed. This paper may provide new ideas for the prevention, diagnosis and treatment of related reproductive diseases.

MIME-Mitosis instead of meiosis and its application in crop apomixis / 生物工程学报

Apomixis has been widely concerned because of its great potential in heterosis fixation. Artificial apomixis is an important direction of current apomixis research. Mitosis instead of Meiosis (MIME) produces diploid gametes that is identical with the maternal genetic composition and is a key step in the artificial creation of apomixes. This paper reviews the occurrence of MIME and its application in crop apomixis and the problems encountered, in an aim to provide reference for expanding the application of MIME in crop apomixis.

Origens do(s) sexo(s) e a rainha dos problemas da biologia evolutiva / Origins of sex(es) and the queen of problems of evolutionary biology

A reprodução sexuada já foi considerada universal, e posteriormente, a forma mais perfeita de reprodução. Todavia, a partir de meados do século XIX, pesquisas no nível celular colocaram em xeque a ideia de que tipos de reprodução assexuadas fossem primitivos ou inferiores. Ao longo do século XX, e adentrando no XXI, hipóteses foram levantadas para explicar as vantagens da reprodução sexuada sobre a assexuada assim como o que permitiria a reprodução sexuada se manter quando seria mais vantajoso se reproduzir de forma assexuada. A mais importante e conhecida é a hipótese da Rainha Vermelha. Paralelamente, vários trabalhos procuraram entrever as pressões ecológicas que permitiram e favoreceram o aparecimento da reprodução sexuada em um cenário situado há cerca de dois bilhões de anos. O objetivo desse trabalho é revisar respostas históricas que marcaram o estudo da origem, da evolução e da manutenção da reprodução sexuada, identificando algumas das principais questões que a comunidade científica elaborou nos últimos duzentos anos.

Sexual reproduction has already been considered universal, and subsequently, the most perfect form of reproduction. However, since the mid-nineteenth century, research at the cellular level has questioned the idea that asexual reproduction types are primitive or inferior. During the twentieth century, and entering the XXI, hypotheses were raised to explain the advantages of sexual reproduction over the asexual as well as what would allow sexual reproduction to be maintained when it would be more advantageous to reproduce asexually. The most important and known is the Red Queen hypothesis. At the same time, several studies have sought to understand the ecological pressures that allowed and favored the appearance of sexual reproduction in a scenario that was around two billion years ago. The aim of this work is to review historical responses that marked the study of the origin, evolution and maintenance of sexual reproduction, identifying some of the main questions that the scientific community has elaborated over the last two hundred years.

Nanos2 in the male reproductive system: Progress in studies / 中华男科学杂志

Nanos2, a member of the Nanos2 gene family, is a specific gene in male germ cells and encodes an evolutionarily conserved RNA binding protein expressed in male primordial germ cells (PGCs) during the embryonic period as well as in the spermatogonial stem cells (SSCs) of the testis. In the embryonic period, Nanos2 promotes the development of male PGCs and inhibits them from meiosis. In the process of spermatogenesis, Nanos2 suppresses the differentiation of SSCs in the testis and maintains the stability of the SSC pool. The knockout of Nanos2 may cause the disappearance of germ cells and sterility in male mice while its overexpression in the testis may lead to accumulation of SSCs in seminiferous tubules. Besides, Nanos2 is involved in the degradation of specific RNAs and possibly associated with some diseases of the male reproductive system. This review focuses on the recent progress in the studies of Nanos2 in the male reproductive system.

Differentiation of pluripotent stem cells into male germ cells: An update / 中华男科学杂志

Pluripotent stem cells (PSCs), including embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), have the potential of differentiating into all types of adult cells. Today, mature functional sperm can be derived from mouse PSCs in vitro, and meanwhile primordial germ cells (PGCs) and meiotic prophase sperm cells can be generated from human ESCs/iPSCs (hESCs/hiPSCs). It is proposed that non-genetic azoospermia might be cured if functional sperm could be obtained from human PSCs (hPSCs) in vitro. It is also possible that healthy functional sperm could be derived from the patient with genetic factor-induced azoospermia by combining iPSCs and gene editing technology. IPSC-derived functional sperm have a higher clinical value for the avoidance of the sperm source and the issue of medical ethics. This article summarizes recent advances in the differentiation of PSCs into male germ cells in vitro, aiming to provide some reference for the treatment of male infertility with PSCs.

Progress in research on meiotic genes underlying primary ovarian insuffiency / 中华医学遗传学杂志

Primary ovarian insuffiency (POI), which accounts for female infertility, is characterized by amenorrhea before the age of 40 and high serum level of follicular stimulating hormone (>40 U/L) at two measurements taken at least one month apart. The disorder is believed to have a strong genetic component. A large number of candidate genes have been proposed, though few of them were extensively studied. With the rapid evolvement of genome sequencing technology, recent research raised the possibility that the genes involved in essential steps of meiosis such as chromosome synapsis and recombination play an important role in the pathogenesis of POI. Clarifying the genetic pathogenesis of POI not only can enhance understanding of the molecular mechanism of reproductive functions and infertility, but also provide accurate information for genetic counseling for such patients.

Influence of epidermal growth factor (EGF) supplementation at different times of in vitro maturation of canine oocytes / Influência da suplementação do fator de crescimento epidermal (EGF) em diferentes momentos da maturação in vitro de oócitos caninos

The aim of this study was to evaluate the influence of epidermal growth factor (EGF) on in vitro maturation of canine oocytes at different times of the process. Ovaries were collected from 55 bitches considered healthy and aseptically isolated, immersed in physiological solution (0.9% NaCl) and transported under refrigeration. Grade 1 cumulus-oocyte complexes (COCs) were selected and divided into two groups: control group (CG) and treatment group (TG). In CG 698 grade I COCs were placed in 4-well plates containing TCM-199 medium supplemented with 25 mM HEPES, 100 IU/mL penicillin, 100 mg/mL streptomycin, 26 mM sodium bicarbonate, 1.5 mM sodium pyruvate, 2.9 mM sodium lactate pentahydrate, 0.6 mM cysteine, 0.03 IU/mL hCG, 0.5 µg/mL FSH, 20 µg/mL estrogen at 38.5ºC in a humidified atmosphere of 5% CO2 in times of 24 h, 48 h, and 72 h. In TG 547 COCs received the same maturation medium plus 10 ηg/mL EGF. Logistic regression models (SAS, 2011) were constructed in order to estimate the chances of oocytes being observed at nuclear maturation stages in different culture times (24 h, 48 h, and 72 h). Based on the results found EGF-supplemented medium showed 2.56 times more chances of having an oocyte at metaphase I (M-I) than medium without EGF (p < 0.0001). The results of this study demonstrated that the time of 72 h showed 5.88 times more chances of having an oocyte at metaphase II (M-II) compared to time of 24 h (p = 0.0001) and 7.69 times more chance than time of 48 h (p = 0.0001). The chances of finding an oocyte at M-II were also 9.09 times higher in medium supplemented with EGF than in medium without EGF (p = 0.0001). Thus, these results demonstrated the essential importance of EGF at different moments of oocyte maturation, being a key component for the acquisition of meiotic competence in bitches, increasing the M-I and M-II rates.(AU)

O objetivo deste estudo foi avaliar a influência do fator de crescimento epidermal (EGF) em diferentes momentos da maturação in vitro de oócitos caninos. Os ovários foram coletados de 55 cadelas consideradas sadias e isolados assepticamente, imersos em solução fisiológica e transportados refrigerados. Os complexos cumulus-oócito (COCs) grau 1 foram selecionados e divididos em dois grupos, denominados grupo controle (GC) e grupo tratamento (GT). No GC, 698 COCs grau I foram cultivados em placas de quatro poços contendo meio TCM-199 suplementado com 25 mM de HEPES, 100 UI/mL de penicilina, 100 mg/mL de estreptomicina, 26 mM de bicarbonato de sódio, 1,5 mM de piruvato de sódio, 2,9 mM de lactato de sódio penta hidratado, 0,6 mM de cisteína, 0,03 UI/mL de hCG, 0,5 µg/mL de FSH, 20 µg/mL de estrógeno em estufa úmida a 38ºC, 5% de CO2 nos períodos de 24h, 48 h e 72 h . Já no GT, 547 COCs receberam o mesmo meio de maturação acrescido de 10 ηg/mL do EGF. Modelos de regressão logística foram elaborados para estimar as chances do oócito ser observado nos estágios de maturação nuclear em diferentes tempos de cultivo. Com base nos resultados encontrados, o meio suplementado com EGF demonstrou 2,56 vezes mais chances de ter um oócito no estágio de metáfase I (M-I) do que o meio sem EGF (p < 0,0001). Os resultados desse estudo demonstraram também que o tempo de 72 h mostrou 5,88 vezes mais chances de ter um oócito no estágio de metáfase II (M-II) do que o tempo de 2 h (p = 0,0001) e 7,69 vezes mais chance do que o tempo de 48h (p = 0,0001). As chances de se encontrar um oócito em M-II também foram 9,09 vezes maiores no meio suplementado com EGF do que no meio sem EGF (p = 0,0001). Dessa forma, estes resultados demonstraram a importância essencial do EGF em diferentes momentos da maturação oocitária, sendo componente chave para a aquisição da competência meiótica nas cadelas, aumentando os índices de M-I e M-II.(AU)

Effects of mono-[2-ethylhexyl] phthalate and DI-[2-ethylhexyl] phthalate administrations on oocyte meiotic maturation, apoptosis and gene quantification in mouse model

Objective: Phthalates, which are commonly used to render plastics into soft and flexible materials, have also been determined as developmental and reproductive toxicants in human and animals. The purpose of this study was to evaluate the effect of mono-[2-ethylhexyl] phthalate [MEHP] and di-[2-ethylhexyl] phthalate [DEHP] oral administrations on maturation of mouse oocytes, apoptosis and gene transcription levels

Materials and Methods: In this experimental study, immature oocytes recovered from Naval Medical Research Institute [NMRI] mouse strain [6-8 weeks], were divided into seven different experimental and control groups. Control group oocytes were retrieved from mice that received only normal saline. The experimental groups I, II or III oocytes were retrieved from mice treated with 50, 100 or 200 micro l DEHP [2.56 micro M] solution, respectively. The experimental groups IV, V or VI oocytes were retrieved from mouse exposed to 50, 100 or 200 micro l MEHP [2.56 micro M] solution, respectively. Fertilization and embryonic development were carried out in OMM and T6 medium. Apoptosis was assessed by annexin V-FITC/Dead Cell Apoptosis Kit, with PI staining. In addition, the mRNA levels of Pou5f1, Ccna1 and Asah1 were examined in oocytes. Finally, mouse embryo at early blastocyst stage was stained with acridine-orange [AO] and ethidium-bromide [EB], in order to access their viability

Results: The proportion of oocytes that progressed up to metaphase II [MII] and 2-cells embryo formation stage was significantly decreased by exposure to MEHP or DEHP, in a dose-dependent manner. Annexin V and PI positive oocytes showed greater quantity in the treated mice than control. Quantitative reverse transcriptase-polymerase chain reaction [qRT-PCR] revealed that expression levels of Pou5f1, Asah1 and Ccna1 were significantly lower in the treated mouse oocytes than control. The total cell count for blastocyst developed from the treated mouse oocytes was lower than the controls

Conclusion: These results indicate that oral administration of MEHP and DEHP could negatively affect mouse oocyte meiotic maturation and development in vivo, suggesting that phthalates could be risk factors for mammalians' reproductive health. Additionally, phthalate-induced changes in Pou5f1, Asah1 and Ccna1 transcription level could explain in part, the reduced developmental ability of mouse-treated oocytes

Effects of sperm insemination on the final meiotic maturation of mouse oocytes arrested at metaphase I after in vitro maturation / 대한생식의학회지

OBJECTIVE: The aims of this study were to investigate whether fertilization could induce the resumption of meiosis in mouse oocytes arrested at metaphase I (MI) after in vitro maturation (IVM), and to investigate the effect of Ca²⁺ chelator treatment at the time of fertilization on the transition from MI to metaphase II (MII). METHODS: MII-stage and arrested MI-stage mouse oocytes after IVM were fertilized, and then embryonic development was monitored. Blastocysts from each group were transferred into 2.5 days post-coitum pseudo-pregnant ICR mice. MI oocytes after IVM were treated with a Ca²⁺ chelator to investigate the effect of Ca²⁺ oscillations on their maturation. RESULTS: As insemination time increased, the number of oocytes in the MI group that reached the MII stage also increased. The blastocyst rates and total cell numbers in the MII group were significantly higher than in the MI group. No pregnancy occurred in the MI group, but 10 pregnancies were achieved (10 of 12) in the MII group. The proportion of MI oocytes that matured to MII oocytes after fertilization was significantly higher in the non-treated group than in the Ca²⁺ chelator-treated group. CONCLUSION: The findings that a higher proportion of MI-arrested oocytes progressed to MII after fertilization and that the MI-to-MII transition was blocked by Ca2+ chelator treatments before fertilization indicate that the maturation of MI oocytes to MII oocytes is associated with intracellular Ca²⁺ oscillations driven by fertilization.

The key role of CYC2 during meiosis in Tetrahymena thermophila

Meiotic recombination is carried out through a specialized pathway for the formation and repair of DNA double-strand breaks (DSBs) made by the Spo11 protein. The present study shed light on the functional role of cyclin, CYC2, in Tetrahymena thermophila which has transcriptionally high expression level during meiosis process. Knocking out the CYC2 gene results in arrest of meiotic conjugation process at 2.5-3.5 h after conjugation initiation, before the meiosis division starts, and in company with the absence of DSBs. To investigate the underlying mechanism of this phenomenon, a complete transcriptome profile was performed between wild-type strain and CYC2 knock-out strain. Functional analysis of RNA-Seq results identifies related differentially expressed genes (DEGs) including SPO11 and these DEGs are enriched in DNA repair/mismatch repair (MMR) terms in homologous recombination (HR), which indicates that CYC2 could play a crucial role in meiosis by regulating SPO11 and participating in HR.

Inducible protective processes in animal systems XV: Hyperthermia enhances the Ethyl methanesulfonate induced adaptive response in meiotic cells of grasshopper Poecilocerus pictus

Purpose: To understand the role of hyperthermia in adaptive response, Ethyl methanesulfonate [EMS] an anticarcinogenic agent, adapted meiotic cells of Poecilocerus pictus was used

Materials and methods: Based on the pilot toxicity study, the effective higher temperatures of 40[degree sign]C and 45[degree sign]C for 15 or 30 min were chosen. P. pictus were treated with conditioning [L] or challenging [H] doses of EMS and 2 h time lag [TL] between these doses [L-2 h-H] was employed. Different treatment schedules were used to analyze the influence of hyperthermia on EMS induced adaptive response namely [i] pre treatment; [ii] inter treatment; [iii] post treatment and [iv] cross adaptation. After each treatment schedule, animals were sacrificed at 12, 24, 36 and 48 h recovery times, testes were processed for meiotic chromosome preparations and anomalies were analyzed

Results: The frequencies of anomalies induced by both conditioning and challenging doses of EMS were significantly higher [p< 0.05] compared to those of the control and hyperthermia groups. The combined treatments resulted in 44-50% reduction compared to additive effect of EMS. The pre, inter, post and cross adaptation treatments with hyperthermia significantly reduced the frequencies of chromosomal anomalies compared to the challenge and combined treatments with EMS at all recovery times [p< 0.05] tested

Conclusion: There is a protection against EMS induced anomalies by hyperthermia in in vivo P. pictus. As far as our knowledge is concerned, this is the first report to demonstrate that hyperthermia enhances the EMS induced adaptive response in in vivo meiotic cells