Effects of testosterone undecanoate as a male contraceptive candidate on rat immunological features

Testosterone undecanoate (TU) is under phase III clinical trial as a hormonal male contraceptive in China. Sex hormones can modulate the immune system. Female hormonal contraceptives may affect SIV/HIV-1 transmission. To evaluate the safety of TU and to understand whether long-term use of TU for a male contraceptive affects users' immunological features, adult male rats were treated for a 32-week TU-treated phase at the dose of 20 mg TU/kg body weight and a 24-week recovery phase. The reproductive and immunological parameters of 4-6 rats in each subgroup were examined at the stated time point. The mean sperm count and viability in the treated rats were significantly suppressed (p < 0.01). In the TU-treated group: the mean blood leukocyte and lymphocyte counts; the proliferation indexes of T cells from peripheral blood mononuclear cells (PBMC) and spleen; and, of B cells from spleen, as well as the mean counts of blood T, NK, and B cells decreased in comparison with those of control group. These decreases were not significant (p > 0.01). Similarly, the mean serum IgM, IgG, and IgA levels and complement activity in TU-treated rats were lower than those in control group (p > 0.01), and the changes in the antibody levels of the examined genital secretions were not significant (p > 0.01). The changes in the thickness of urethra epithelium, and in secretory component (SC) expression in genitals were not observed in the treated group. These results demonstrated that long-term supraphysiological TU injection did not obviously affect the examined rat immunological parameters.

Sexual behavior in a one-male unit of Rhinopithecus bieti in captivity

Data regarding the sexual behavior of black-and-white snub-nosed monkeys (Rhinopithecus bieti) were collected in 1998 in a one-male unit in captivity by all-occurrences sampling during the mating season. Before the present study, little was known about the sexual behavior of this species. This study showed that female solicitation is mainly expressed as "prostration plus glancing laterally" (PG) or "sitting plus head moving up and down" (HM), and male solicitation is exhibited by the "grunt bared-teeth display." The mount-to-ejaculation ratio was 5.2 on average, and single-mount ejaculations (SMEs) were observed in only 4.4% of mounts on days with at least one ejaculation. Therefore, the main copulatory pattern of this species is multiple-mount ejaculation (MME). Females initiated 72% of 18 ejaculatory mounts. Females initiated more ejaculatory mounts than non-ejaculatory ones. In general, the patterns of sexual behavior in this species are similar to those reported for other Colobines. (C) 2004 Wiley-Liss, Inc.

Physiological responses to capture and handling of free-ranging male Yangtze finless porpoises (Neophocaena phocaenoides asiaeorientalis)

We captured free-ranging male Yangtze finless porpoises over three seasons and assayed leukocytes and serum biochemistry to investigate physiological responses to the capture and handlings. Serum thyroid hormones (THs) declined sharply in those porpoises compared with hormone variation in a captive male finless porpoise. Hypernatremia and hypokalemia were also significant in the free-ranging animals suggesting that conservation of serum sodium might be acutely vital for this freshwater subspecies. The animals captured in spring showed more significant neutrophilia and eosinopenia than those captured in autumn suggesting that they may be more affected by capture during the breeding season. Furthermore, physical examination of porpoises when out of the water was apparently stressful, particularly when they were kept out of the water for longer periods. However, an increase in circulating THs may be an adaptive response to accommodate these short-term stresses.

Isolation of Y- and X-linked SCAR markers in yellow catfish and application in the production of all-male populations

P>Sex controls have been performed in some farmed fish species because of significant growth differences between females and males. In yellow catfish (Pelteobagrus fulvidraco), adult males are three times larger than female adults. In this study, six Y- and X-linked amplified fragment length polymorphism fragments were screened by sex-genotype pool bulked segregant analysis and individual screening. Interestingly, sequence analysis identified two pairs of allelic genes, Pf33 and Pf62. Furthermore, the cloned flanking sequences revealed several Y- and X-specific polymorphisms, and four Y-linked or X-linked sequence characterized amplified region (SCAR) primer pairs were designed and converted into Y- and X-linked SCAR markers. Consequently, these markers were successfully used to identify genetic sex and YY super-males, and applied to all-male population production. Thus, we developed a novel and simple technique to help commercial production of YY super-males and all-male populations in the yellow catfish.

Discovery of a male-biased mutant family and identification of a male-specific SCAR marker in gynogenetic gibel carp Carassius auratus gibelio

Gibel carp ( Carassius auratus gibelio) is a uniquely gynogenetic species with a minor ratio of males in natural habitats, but its male origin and sex determination mechanisms have been unknown. In this study, a male-biased mutant family was discovered from the gynogenetic gibel carp, and a male-specific SCAR marker was identified from the mutant family. Normal spermatogenesis was observed in the male testes by immuno. fluorescence histochemistry. Nearly identical AFLP profiles were observed between males and females, but a male-specific 86 bp AFLP fragment was screened by sex-pool bulked segregant analysis and individual screening. Based on the male-specific AFLP fragment, a total of 579 bp sequences were cloned by genome walking. Subsequently, a male-specific SCAR marker was designed, and the male-specific DNA fragment was confirmed to be steadily transmitted to the next generation and consistently detected only in males. (C) 2009 National Natural Science Foundation of China and Chinese Academy of Sciences. Published by Elsevier Limited and Science in China Press. All rights reserved.

Involvement of Fas/FasL system in apoptotic signaling in testicular germ cells of male Wistar rats injected i.v. with microcystins

Previous studies have shown that gonads were the second target organ of microcystins (MCs), and that MCs exposure exerted obvious toxic effects on male reproductive system of mammals. However, relevant molecular evidences are still lacking. Fas-signaling pathway plays a key role in toxicant-induced germ cell apoptosis. This study was to evaluate the responses of Fas/FasL system related genes and proteins in testes of rats injected intravenously with MCs. Enhanced apoptosis of germ cells in the testes of MCs-treated rats was detected by the terminal deoxynucleotidyl transferase-mediated deoxy-UTP nick end labeling (TUNEL) associated with up-regulation of the Fas/FasL system. Both Fas and FasL protein expression were induced evidently from I h post-injection, and this high expression level maintained throughout the experiment. In addition, the activation of caspase-8 and caspase-3 protein was also observed, which were indicators of apoptosis. These results suggested the likely involvement of Fas/FasL system in the MCs-induced germ cell apoptosis. It is also suggested that MCs can cause damage to Sertoli cells directly. (C) 2009 Elsevier Ltd. All rights reserved.

In vivo study on the effects of microcystin extracts on the expression profiles of proto-oncogenes (c-fos, c-jun and c-myc) in liver, kidney and testis of male Wistar rats injected i.v. with toxins

Microcystins (MCs) are a potent liver tumor promoter, possessing potent tumor-promoting activity and weak initiating activity. Proto-oncogenes are known to be involved in the tumor-promoting mechanisms of microcystin-LR. However, few data are available on the effects of MCs oil proto-oncogenes in the whole animal. To investigate the effects of MCs on the expression profile of the proto-oncogenes in different organs, male Wistar rats were injected intravenously with microcystin extracts at a dose of 86.7 mu g MC-LR eq/kg bw (MC-LR eq, MC-LR equivalents). mRNA levels of three proto-oncogenes c-fos, c-jun and c-myc in liver, kidney and testis were analyzed using quantitative real-time PCR at several time points post-injection. Significant induction of these genes at transcriptional level was observed in the three organs. In addition, the increase of mRNA expression of all three genes was much higher in liver than in kidney and testis. Meanwhile, the protein levels of c-Fos and c-Jun were investigated by western blotting. Both proteins were induced in the three organs. However, elevations of protein levels were Much lower than those of mRNA levels. These findings suggest that the expression of c-fos, c-jun and c-myc might be one possible mechanism for the tumor-promoting activity and initiating activity of microcystins. (c) 2008 Published by Elsevier Ltd.

Elevated levels of urinary 8-hydroxy-2'-deoxyguanosine in male electrical and electronic equipment dismantling workers exposed to high concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans, polybrominated diphenyl ethers, and polychlorinated biphenyls

To investigate the occupational exposure levels to polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polybrominated diphenyl ethers (PBDEs), and polychlorinated biphenyls (PCBs), indoor dust (n = 3) in workshops and hair samples from male workers (n = 64) were collected at two electrical and electronic equipment waste (E-waste) dismantling factories located in the LQ area in east China in July 11-13, 2006. Pre- and postworkshift urines (64 of each) were also collected from the workers to study oxidative damage to DNA using 8-hydroxy-2'-deoxyguanosine (8-OHdG) as a biomarker. The concentrations of PCDD/Fs, PCDD/F-WHO-TEQs, PBDEs, PCBs and PCB-WHO-TEQs were (50.0 +/- 8.1) x 10(3), 724.1 +/- 249.6, (27.5 +/- 5.8) x 10(6), (1.6 +/- 0.4) x 10(9), (26.2 +/- 3.0) x 10(3) pg/g dry weight (dw) in dust, and (2.6 +/- 0.6) x 10(3), 42.4 +/- 9.3, (870.8 +/- 205.4) x 10(3), (1.6 +/- 0.2) x 10(6), 41.5 +/- 5.5 pg/g dw in hair, respectively. The homologue and congener profiles in the samples demonstrated that high concentrations of PCDD/Fs, PBDEs, and PCBs were originated from open burning of E-waste. The 8-OHdG levels were detected at 6.40 +/- 1.64 mu mol/mol creatinine in preworkshift urines. However, the levels significantly increased to 24.55 +/- 5.96 mu mol/mol creatinine in postworkshift urines (p < 0.05). Then, it is concluded that there is a high cancer risk originated from oxidative stress indicated by the elevated 8-OHdG levels in the E-waste dismantling workers exposed to high concentrations of PCDD/Fs, PBDEs, and PCBs.

Deceptive female oviposition behaviour elicits male ejaculation in the European bitterling

In European bitterling Rhodeus amarus, fish that lay their eggs in the gill chambers of living freshwater mussels, females perform conspicuous behaviours associated with spawning that increases the probability of males performing ejaculatory behaviour and participating in a spawning. A significant positive association was detected between behaviour in which a female performs a spawning action but without releasing eggs, here termed 'deceptive female oviposition', and ejaculatory behaviour by courting males.

EST-based identification of genes expressed in the hypothalamus of male orange-spotted grouper (Epinephelus coioides)

The orange-spotted grouper, Epinephelus coioides, is an important marine aquaculture fish, but its large-scale aquaculture has been hindered by the rarity of natural males because it is a protogynous hermaphroditic fish. Hypothalamus-pituitary-gonad is an important endocrine axis in regulating reproduction and sex differentiation. To reveal the molecular mechanism of hypothalamic physiological functions, we performed he studies on identification of genes expressed in the hypothalamus of male orange-spotted grouper using EST and RT-PCR strategy. A total of 1006 ESTs were sequenced, and 402 (39.96%) clones were identified as known genes and 604 (60.04%) as unknown genes. The 402 clones of known gene products represent transcripts of 18 1 genes. Moreover, the expression patterns of 26 unknown genes were analyzed in various tissues, such as liver, kidney, spleen, fat, heart, muscle, pituitary, hypothalamus, telencephalon, cerebellum, midbrain, medulla oblongata, ovary and testes. Five different categories of expression patterns were observed from them. Several unknown ESTs, such as DN551996, DN551998, DN552082, and DN552070, were detected to be hypothalamus-specific, brains-specific, or hypothalamus and gonad-specific genes. Interestingly, DN551996, not only exhibiting expression differences between ovary and testis, but also showing sex-dependent differences in hypothalamus of grouper, might play significant role in grouper reproduction or sex inversion. Further functional studies on these genes will provide more information on molecule regulation mechanism of sex inversion in groupers. (c) 2006 Elsevier B.V All fights reserved.

Reproductive seasonality and maturity of male Neophocaena phocaenoides asiaeorientalis in captivity: A case study based on the hormone evidence

To provide hormone evidence on reproductive seasonality and maturity of the Yangtze finless porpoise, the authors monitored the monthly variations of serum reproductive hormones of a male Yangtze finless porpoise in captivity via radioimmunoassay from 1997 to 2003. It was demonstrated that the immature animal had a serum T level of 28-101ngdL -1 (6552ngdL -1 ), reached puberty with the serum T concentration ranging between 250 and 590ngdL -1 (390130ngdL -1 ), and attained reproductive maturity when the serum T level went beyond 1120180ngdL -1 in the breeding season. The body length growth of the animal showed a pattern similar to the serum T variations during its adolescent period from the age of 4 to 6 years. Moreover, the serum T concentration of the male porpoise exhibited significant seasonal variations, indicating that its breeding season may start as early as March and end as late as September.

First description of the male and redescription of the female of Philometra clavaeceps Dogiel and Akhmerov, 1959 (Nematoda : Philometridae), a parasite of east Asian cyprinid fish

The first description of the male and a redescription of the female of the nematode Philometra clavaeceps Dogiel and Akhmerov, 1959, a parasite of east Asian cyprinids, are presented on the basis of specimens collected from Culter erythropterus Basilewsky and Culler dabryi Bleeker from Liangzi Lake (the Yangtze River basin), Hubei Province, central China. Gravid females from the fish abdominal cavity, penetrating often into ovaries, occurred in May-June, whereas conspecific males and young mature females on the swimbladder were recorded in January. Philometra clavaeceps seems to have a pronounced annual maturation cycle in the locality. The finding of P. clavaeceps in C. dabryi represents a new host record.

同源四倍体水稻三系亲本的遗传差异、细胞遗传学比较研究及低直链淀粉含量突变体Wx基因序列分析

同源四倍体水稻（2N=4X=48,AAAA）是由二倍体水稻（2N=2X=24,AA）通过秋水仙素诱导染色体加倍后得到的新品系，具有优良的抗病性以及较高的蛋白质含量。因此，在四倍体水平上挖掘水稻的增产潜力成为水稻育种的新手段。同源四倍体水稻具有很强的遗传可塑性和很弱的遗传保守性，利用其作为水稻远缘杂交的桥梁，从野生物种中不断地引进有益的基因，这将有助于杂交水稻的多代利用和固定水稻的杂种优势。但是迄今为止，还没有关于同源四倍体水稻遗传多样性，遗传背景的报道。目前世界关于同源四倍体水稻的研究主要集中在中国，主要研究方向为培育、筛选结实正常的亲本材料，配置和筛选结实率正常或接近正常的组合。经过几十年研究，虽然在材料构建，细胞学研究等方面取得了较大进展，但同样由于结实率低的瓶颈问题未解决，而使多倍体水稻育种未能取得实质性进展。而近年来一些关于同源四倍体水稻低结实率机理的细胞学研究也由于缺乏统计学数据而缺乏说明性。本文用SSR标记，对选取的36个结实率正常同源四倍体水稻三系亲本和14个来源二倍体亲本，分析他们的遗传差异和群体遗传结构。本文还利用我们培育的高、低结实率的同源四倍体水稻恢复系、优良保持系和杂种F1及二倍体对照为材料，进行系统深入的细胞遗传学研究，进一步探讨同源四倍体水稻有性传递后代的发育过程，探索分裂期染色体行为特征与遗传性状稳定性的关系，为进一步选育多倍体水稻品种并将其应用于生产提供理论依据。同源四倍体水稻突变株D4063-1直链淀粉含量比来源二倍体明恢63下降一半,即其直链淀粉含量为5.23%，为研究其直链淀粉含量下降的原因，本文还根据普通水稻Wx基因设计引物，扩增测序获得了D4063-1Wx基因的全序列，与已报道Wx基因进行比对分析，并根据D4063-1和籼稻、粳稻的序列差异并根据D4063-1在该片段上的特征序列位点设计了用于识别D4063-1的寡核苷酸片段,为快速、准确的鉴别低直链淀粉的D4063-1创造了条件。 SSR标记具有基因组分布广泛、数量丰富、多态性高、容易检测、共显性、结果稳定可靠、实验重现性好、操作简单、经济、易于高通量分析等许多优点，被认为是用于遗传多样性、品种鉴定、物种的系统发育、亲缘关系及起源等研究的非常有效的分子标记。本研究选取了中国科学院成都生物所培育的同源四倍体和二倍体水稻亲本，并用36个微卫星标记进行了遗传差异和种群遗传结构分析。在50个品系中，我们观察到较高水平的多态性，每基因等位基因数（Ae）分布于2至6之间（平均值3.028），多态性信息含量（PIC）分布于0.04至0.76之间（平均值0.366）；期望杂合度（He）分布于0.04至0.76之间（平均值0.370），Shannon指数（I）分布于0.098至1.613之间（平均值0.649）。同源四倍体品系的等位基因数，期望杂合性和Shannon指数都比二倍体品系高。在供试50个品系中，较多材料均发现Rare基因，根据SSR多态性指数我们构建了同源四倍体和二倍体水稻的核心指纹库。F-统计值表明遗传差异主要存在于同源四倍体品系中（Fst=0.066）。聚类分析结果表明50个品系可以分为4个组。I组包括所有的同源四倍体和二倍体籼稻保持系，以及一个同源四倍体籼稻雄性不育系及其来源二倍体。II组仅包括IR来源的品系。III组比II组和IV组更复杂，包括同源四倍体和二倍体籼稻恢复系品系。IV组包括同源四倍体和二倍体粳稻品系。此外,由于等位基因及配子的遗传差异,同源四倍体与二倍体品系中存在单位点和双位点的遗传差异。分析结果表明,二倍体和四倍体水稻基因库的不同,其中遗传变异可以区分四倍体与二倍体水稻。同源四倍体水稻具有长期而独立的遗传性，我们能够选育并得到与二倍体亲本相比有特殊优良农艺性状的品系。 本研究以高结实率的同源四倍体水稻恢复系DTP-4、D明恢63及优良保持系D46B为材料进行农艺性状及细胞遗传学比较研究。DTP-4、D明恢63及保持系D46B的的染色体组成均为2N=4X=48，花粉母细胞具有较为理想的减数分裂行为，配对染色体的比率在99%以上，这与理论染色体组构成相符。DTP-4和D明恢63PMC减数分裂各个时期单价体和三价体的比例都非常低，而在MI， PMC观察到较多的二价体和四价体且四价体多以环状形式出现，其最大频率的染色体构型分别为12II 6IV和10II 7IV。恢复系DTP-4和D明恢63在MI四价体频率分别为2.00/PMC和2.26/PMC，而保持系D46B在MI四价体频率为6.00/PMC，极显著地高于恢复系品系，表明保持系D46B具有更好的染色体配对性质；AI保持系D46B的染色体滞后频率为10.62%，远低于恢复系材料DTP－4和D明恢63的19.44％和23.14％，接近二倍体对照明恢63的7.30%水平；TI保持系D46B具有比恢复系更低频率的微核数。而在TII，D46B的正常四分小孢子比率不但高于恢复系品系甚至高于二倍体对照。对高低结实率的同源四倍体水稻恢复系和杂种F1代的花粉育性，结实率和细胞遗传学行为进行了比较研究。DTP-4, D明恢63, D46A´DTP-4和D46A´D明恢63的花粉育性和结实率比D什香和D46A´D什香显著提高。减数分裂分析的结果表明，DTP-4，D明恢63，D什香，D46A´DTP-4，D46A´D明恢63和D46A´D什香其减数分裂染色体构型分别为：0.05I +19.96 II (9.89棒状+10.07环状) +0.01III + 2.20 IV, 0.11I +19.17 II (8.90 棒状+10.37 环状) +0.09III + 2.26 IV + 0.01 VI, 1.33I +9.46 II (4.50 棒状+4.96 环状) +0.44III + 6.02 IV + 0.09VI + 0.09 VIII, 0.02I +14.36 II (6.44 棒状+7.91 环状) +0.01III + 4.80IV + 0.01VIII, 0.06 I +17.67 II (11.01 棒状+6.67 环状) +0.06 III + 3.10 IV + 0.01 VI and 1.11 I +11.31 II (5.80 棒状+5.51 环状) +0.41 III + 5.63 IV+0.03VI+0.03VIII。在同源四倍体水稻恢复系和杂种F1代材料中，最常见的染色体构型为16II +4IV和12II +6IV。在减数分裂过程中，结实率较高的材料染色体异常现象较少而结实率较低的材料染色体异常现象较严重。在杂种F1代中，二价体的比例要低于其相应的恢复系亲本，同样的，单价体，三价体和多价体的比例相比其恢复系亲本也偏低。然而，在减数分裂MI，杂种F1代中四价体的比例要显著高于其恢复系亲本。在中期I，每细胞单价体的比例和花粉育性呈现出极高的负相关(-0.996)，当单价体数目升高时，花粉育性下降。其次是每细胞三价体的比例(-0.987)，之后则是每细胞多价体的比例与花粉育性的负相关(-0.948)。但是统计分析表明，二价体和四价体的比例对花粉育性和结实率没有显著影响。这一结果表明出了花粉育性和细胞减数分裂行为的相关性，同源四倍体的减数分裂行为为筛选高结实率的同源四倍体种系提供了理论依据。 突变体是遗传学研究的基本材料。利用突变体克隆水稻基因,并进而研究基因的生物学功能是水稻功能基因组学的重要研究内容。本课题组在多年的四倍体水稻育种研究中已获得多个低直链淀粉含量突变体，其中一些突变体在直链淀粉含量下降的同时，胚乳外观也发生了显著改变，呈半透明或不透明。同源四倍体水稻突变株D4063-1直链淀粉含量比来源二倍体明恢63下降一半,即其直链淀粉含量为5.23%。为研究其直链淀粉含量下降的原因，我们根据普通水稻Wx基因设计引物，扩增测序获得了D4063-1Wx基因的全序列，与已报道Wx基因进行比对分析；同源四倍体水稻D4063-1Wx基因最显著变化为在外显子序列中发生了碱基缺失，导致移码突变，在第9外显子终止密码子提前出现。D4063-1Wx基因碱基位点的变化还导致了其序列上的酶切位点的变化,对常用限制性内切酶位点分析分析结果表明同源四倍体水稻相对于籼稻和粳稻多了2个sph1酶切位点，相对于粳稻减少了6个Acc1，增加了4个Xba1，1个Xho1，1个Pst1和1个Sal1酶切位点。聚类分析表明D4063-1Wx基因序列与籼稻亲源关系较近，由此推测D4063-1Wx基因来源于籼稻的Wxa基因型。另外，根据D4063-1Wx基因的碱基差异，我们推测D4063-1Wx基因外显子碱基变化导致的RNA加工障碍是其直链淀粉降低的主要原因，并可能与其米饭较软等品质相关。本文还根据D4063-1和籼稻、粳稻的序列差异并根据D4063-1在该片段上的特征序列位点设计了用于识别D4063-1的寡核苷酸片段,并作为PCR反应的引物命名为AUT4063-1,将该引物与我们设计的扩增普通籼稻、粳稻的Wx基因引物F5配合使用建立了识别D4063-1的显性和共显性两种检测方式的分子标记,为快速、准确的鉴别低直链淀粉的D4063-1创造了条件。 研究同源四倍体水稻基因组的遗传差异，探索同源四倍体水稻的遗传规律，研究分裂期染色体行为特征与遗传性状稳定性的关系,旨在揭示四倍体水稻中同源染色体配对能力的遗传差异，为进一步选育多倍体水稻品种并将其应用于生产提供理论依据。 Autotetraploid rice (2N=4X=48, AAAA) is a new germplasm developed from diploid rice (2N=2X=24, AA) through chromosomes doubling with colchicines and is an excellent resource for desirable resistance genes to the pathogens and high protein content. Therefore, heterosis utilization on polyploidy is becoming a new strategy in rice breeding. At present, the main research on autotetraploid rice centralizes in China. Breeding effort has been made to improve autotetraploid rice genetically, however, the progresses are limited due to higher degree of divergence between hybrid sterility and polygenic nature. But to date, almost nothing is reported about the genetic diversity, original and genetic background of autotetraploid rice. Despite several reports on cytological analysis of the mechanisms of low seed set in autotetraploid rice still the results are inconclusive due to lack the statistical evaluation. Therefore, the study on the mechanisms of low seed set in autotetraploid is a priority for rice breeding. Microsatellites or simple sequence repeats (SSRs) are the widely used marker for estimating genetic diversity in many species, including wild, weedy, and cultivated rice. In our research, genetic diversity and population genetic structure of autotetraploid and diploid populations collected from Chengdu Institute of Biology, Chinese Academy of Sciences were studied based on 36 microsatellite loci. For the total of 50 varieties, a moderate to high level of genetic diversity was observed at population levels with the number of alleles per locus (Ae) ranging from 2 to 6 (mean 3.028) and PIC ranging from 0.04 to 0.76 (mean 0.366). The expected heterozygosity (He) varied from 0.04 to 0.76 with the mean of 0.370 and Shannon’s index (I) ranging from 0.098 to 1.613 (mean 0.649). The autotetraploid populations showed a slightly higher level of effective alleles, the expected heterozygosity and Shannon’s index than that of diploid populations. Rare alleles were observed at most of the SSR loci in one or more of the 50 accessions and core fingerprint database of the autotetraploid and diploid rice was constructed. The F-statistics showed that genetic variability mainly existed among autotetraploid populations rather than among diploid populations (Fst=0.066). Cluster analysis of the 50 accessions showed four major groups. Group I contained all of the autotetraploid and diploid indica maintainer lines and a autotetraploid and its original diploid indica male sterile lines. Groups II contained only original of IR accessions. Group III was more diverse than either group II or IV and comprised of both autotetraploid and diploid indica restoring lines. Group IV included japonica cluster of the autotetraploid and diploid rices. Furthermore, genetic differences at the single-locus and two-locus levels, as well as components due to allelic and gametic differentiation, were revealed between autotetraploid and diploid varieties. This analysis indicated that the gene pools of diploid and autotetraploid rice are somewhat dissimilar, which made a variation that distinguishes autotetraploid from diploid rices. Using this variation, we can breed new autotetraploid varieties with some new important agricultural characters but the diploid rice has not. Cytogenetic characteristics in restorer lines DTP-4, DMinghui63 and maintainer line D46B of autotetraploid rices were studied. DTP-4, DMinghui63 and D46B showed the advantage of high seed set and biological yield. The meiotic chromosome behavior was slightly irregular in DTP-4, DMinghui63 and D46B. We observed less univalent, trivalent and multivalent at MI, but more bivalent and quadrivalent were observed. The most frequent chromosome configurations were 12II 6IVand 10II 7IV in restorer and maintainer lines, respectively. The quadrivalent frequency of DTP-4 and Dminghui63 at metaphase(MI) was respectively 2.00/PMC and 2.26/PMC. However that frequency of D46B was 6.00/PMC, which was greatly significantly higher than DTP-4 and Dminghui63. That indicates the maintainer D46B has better chromosome pairing capability in metaphase (MI). The frequency of lagging chromosomes of the maintainer D46B at anaphaseI (AI) was 10.62%, which was significantly lower than that of DTP-4(19.44%) and Dminghui63(23.14%) and nearly reaching the level of diploid CK(7.30%). In telophaseI (TI) maintainer D46B showed lower frequency of microkernel at TI and lower frequency of abnormal spores at telophaseII(TII). We also studied pollen fertility, seed set and cytogenetic characteristics of restorer lines and F1 hybrids of autotetraploid rice. DTP-4, DMinghui63, D46A´DTP-4 and D46A´DMinghui63 showed significantly higher pollen fertility and seed set than DShixiang and D46A´DShixiang. Pairing configurations in PMC of DTP-4, DMinghui63, DShixiang, D46A´DTP-4, D46A´DMinghui63 and D46A´DShixiang were 0.05 I+19.96 II (9.89 rod+10.07 ring)+0.01 III+2.20 IV, 0.11 I+19.17 II (8.90 rod+10.37 ring)+0.09 III+2.26 IV+0.01 VI, 1.33 I+9.46 II (4.50 rod+4.96 ring)+0.44 III+6.02 IV+0.09 VI+0.09 VIII, 0.02 I+14.36 II (6.44 rod+7.91 ring)+0.01 III+4.80 IV+0.01V III, 0.06 I+17.67 II (11.01 rod+6.67 ring)+0.06 III+3.10 IV+0.01 VI and 1.11 I+11.31 II (5.80 rod+5.51 ring)+0.41 III+5.63 IV+0.03 VI+0.03 VIII, respectively. Configuration 16 II+4 IV and 12 II+6 IV occurred in the highest frequency among the autotetraploid restorers and hybrids. Meiotic chromosome behaviors were less abnormal in the tetraploids with high seed set than those with low seed set. The hybrids had fewer frequencies of bivalents, univalents, trivalents and multivalents than the restorers, but higher frequency of quatrivalents than the restorers at MI. The frequency of univalents at M1 had the most impact on pollen fertility and seed set, i.e., pollen fertility decreased with the increase of univalents. The secondary impact factors were trivalents and multivalents, and bivalents and quatrivalents had no effect on pollen fertility and seed set. The correlative relationship between pollen fertility and cytogenetic behaviors could be utilized to improve seed set in autotetraploidy breeding. The amylose content of autotetraploid indica mutant Rice D4063-1 dropped by half than diploid Minghui 63, that is, its amylose content of 5.23%.The whole sequence of Waxy gene of D4063-1 is amplified and sequenced. And the discrepancy of bases is found comparing to the reported Waxy gene. The Waxy gene of autotetraploid Rice D4063-1 had a base deletion in exon sequence, which resulted frameshift mutation in exon 9 and termination codon occur early. The mutation of Wx also led to the change of some common restriction endonuclease sites. Results showed compared to indica and japonica, D4063-1 had two adding sph1 sites. Compared to japonica, D4063-1 had six decreasing Acc1, a adding Xho1, Pst1 and Sal1 restriction sites. Phylogeny analysis shows that the DNA sequence of Waxy gene of D4063-1 is closer to Indica, and we suppose that the Waxy gene of D4063-1 is origin from genotype Wxa. In addition, according to the base differences of Wx in D4063-1, we deduce that RNA processing obstacle led by base change of intron is the main cause to low the amylose content, and related to phenotype of its soft rice. Based on analysis of fragments of D4063-1, indica and japonica and according to the special point of the three species, primers as markers-AUT4063-I were designed for distinguishing the D4063-1 from other rice. Combining with primer pair F5, dominant and codominant ways were established for discriminating them., rapid and correct identification of D4063-1 from other rice could be done. The genetic analysis is important to ensure the original of autotetraploid rice, for maintaining the “distinctiveness” of autotetraploid varieties, and to differentiate between the various genetic background of autotetraploid rice. The autotetraploid breeding will benefit from detailed analysis of genetic diversity in the germplasm collections. Further investigation on mechanisms of meiotic stability should benefit polyploid breeding. These findings demonstrated opportunity to improve meiotic abnormalities as well as grain fertilities in autotetraploid rice.