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1.
A circannual analysis was made of serum cortisol, luteinizing hormone (LH), and testosterone concentrations in the male clouded leopard (Neofelis nebulosa). Group I males (n = 4), maintained in a standardized environment, were bled serially during a regimented anesthesia/electroejaculation episode occurring monthly (beginning in January, ending in December). Additional sampling intervals were conducted under anesthesia only (control, n = 8), anesthesia plus a single adrenocorticotropin hormone challenge (ACTH, Cortrosyn, n = 4), or anesthesia plus a single 25 micrograms injection of gonadotropin-releasing hormone (GnRH, Gonadorelin, n = 4). Group II males (n = 6) from various zoological collections were sampled serially under the same semen collection conditions on one random occasion within the year. Serum cortisol levels were 2 times greater than values measured in comparable studies involving other felid species. Cortisol concentrations were similar during electroejaculation and control (anesthesia only) episodes, and mean levels did not rise as a result of semen collection. Adrenocorticotropin caused an immediate rise in cortisol to levels at least 1.5 times greater than electroejaculated or control counterparts. Mean concentrations of basal cortisol in individual males gradually increased as the year progressed, possibly as a consequence of repeated psychogenic stress. Between seasons, there were no differences in mean LH; however, testosterone levels were greater (p less than 0.05) in the winter compared to all other seasons. There were no differences (p greater than 0.05) between individual males in secretory patterns or mean concentrations of cortisol, LH, or testosterone. Within males, distinct temporal fluctuations were observed in both LH and testosterone during the approximately 80-min sampling interval. Neither LH nor testosterone profiles appeared affected by cortisol patterns during electroejaculation or after an ACTH challenge. A bolus of GnRH induced a marked rise in serum LH and testosterone within 15 and 30 min respectively, indicating that these two hormones were coupled. Both LH and testosterone profiles in Group II males mimicked those in Group I; concentrations of cortisol in Group II males immobilized on one occasion were similar to those of Group I animals sampled from January-May but appeared to be less than values measured from June-December. These data demonstrate that the clouded leopard, compared to other felids, produces markedly elevated concentrations of cortisol, which are likely related to an aggressive behavioral temperament.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
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3.
Nadja C. Wielebnowski Norah Fletchall Kathy Carlstead Juan M. Busso Janine L. Brown 《Zoo biology》2002,21(1):77-98
The North American clouded leopard (Neofelis nebulosa) population is far from self‐sustaining. Breeding success is poor and behavioral problems (i.e., fur‐plucking, tail‐chewing, excessive hiding or pacing, and intersexual aggression that results in mate killing) are common. This study was undertaken to investigate whether some of these problems may be indicators of chronic stress (as reflected by persistently elevated glucocorticoid levels) and whether they are associated with specific management factors. A fecal corticoid metabolite assay was validated to monitor adrenal activity in clouded leopards. Adrenocorticotropic hormone (ACTH) challenges conducted in four clouded leopards established the biological relevance of the assay system. Fecal corticoid concentrations increased 14‐fold above baseline within 24 hours after ACTH administration. Adrenal activity then was monitored in 72 (36 males; 36 females) clouded leopards (65% of the North American Species Survival Plan population) during a 6‐week period and compared to husbandry and behavior data. There was a significant (P < 0.01) gender difference in fecal corticoid concentrations, with females producing higher concentrations than males. Multiple regression analyses revealed negative associations (P < 0.01) between enclosure height, number of hours keepers spent with each animal per week, and corticoid concentrations. A positive correlation (P < 0.001) was found between the number of keepers caring for an individual and corticoid concentrations. Higher fecal corticoid concentrations (P ≤ 0.05) were measured in clouded leopards kept on public display or near potential predators compared to individuals maintained off exhibit or in the absence of predators. Individuals that performed self‐injuring behaviors also had elevated fecal corticoids (P < 0.01). Spearman‐rank correlation analysis of keeper ratings and hormone data revealed positive associations (P ≤ 0.05) between some behaviors (pace, sleep, hide, and fearful/tense) and fecal corticoid concentrations. Overall these results indicate that noninvasive fecal corticoid monitoring has enormous potential for investigating how management and behavioral problems are related to animal well‐being. If conducted under carefully controlled experimental paradigms, this technique could allow researchers and managers to identify problem areas of captive management for clouded leopards (e.g., enclosure height, keeper time) and evaluate the efficacy of strategies designed to promote animal welfare and increased reproductive success. Zoo Biol 21:77–98, 2002. © 2002 Wiley‐Liss, Inc. 相似文献
4.
D E Wildt L G Phillips L G Simmons P K Chakraborty J L Brown J G Howard A Teare M Bush 《Biology of reproduction》1988,38(2):245-255
Male cheetahs, tigers, leopards, and pumas maintained under the same conditions were anesthetized and 1) serially bled before, during, and after electroejaculation (EE); 2) serially bled only (AO); or 3) serially bled before and after receiving adrenocorticotropin hormone (ACTH). Ejaculates from leopards contained higher (p less than 0.05) sperm concentrations than cheetahs and pumas but lower (p less than 0.05) sperm motility ratings than all other species. Tigers produced a larger seminal volume and the greatest number of motile sperm/ejaculate (p less than 0.05). The percentage of morphologically abnormal spermatozoa was greater (p less than 0.05) in cheetahs (64.6%), leopards (79.5%), and pumas (73.5%) than in tigers (37.5%). The most prevalent spermatozoal deformities included a tightly coiled or bent flagellum, a deranged midpiece, or a residual cytoplasmic droplet. Mean baseline serum cortisol concentrations in leopards were 2- and 4-fold greater (p less than 0.05) than in tigers and cheetahs, respectively. Basal cortisol concentrations in pumas were similar to those of tigers, but irrespective of treatment increased 2-fold (p less than 0.01) during the bleeding period. An acute rise and fall in cortisol attributable to EE was observed only in cheetahs. In tigers and leopards, mean peak cortisol concentrations after ACTH were similar to maximal values observed after EE. However, peak cortisol levels in cheetahs and pumas after ACTH were greater (p less than 0.01) than the concentrations measured after EE, indicating that these manipulatory procedures were not eliciting a maximal adrenal response. In the EE groups, luteinizing hormone (LH) and testosterone levels in cheetahs were lower (p less than 0.05) than in other species, whereas levels of both hormones were comparable (p greater than 0.05) in tigers, leopards, and pumas. Elevated cortisol levels in cheetahs and pumas had no discernible effect on LH/testosterone patterns; however, the results were equivocal in tigers, and, among leopards, testosterone concentrations consistently declined over time. In this study, using a standardized approach, we identify different ejaculate and endocrine characteristics of captive cheetahs, tigers, leopards, and pumas. The data extend earlier observations and demonstrate that some, but not all, Felidae species ejaculate high numbers of pleiomorphic spermatozoa. However, inter-species differences in sperm integrity do not appear related to inter-species variations in cortisol, LH, or testosterone. The observation of continuously declining testosterone concentrations only in leopards after AO, EE, or ACTH treatment suggests that rising and/or elevated cortiso 相似文献
5.
Similarity in ejaculate-endocrine characteristics in captive versus free-ranging cheetahs of two subspecies 总被引:3,自引:0,他引:3
D E Wildt S J O'Brien J G Howard T M Caro M E Roelke J L Brown M Bush 《Biology of reproduction》1987,36(2):351-360
Ejaculate-endocrine characteristics were measured in 23 captive cheetahs (Acinonyx jubatus jubatus) in North American zoos and in 8 free-ranging cheetahs (A.j. raineyi) in eastern Africa (Tanzania). A standardized electroejaculation protocol was used, and numbers of motile spermatozoa were similar (p greater than 0.05) between groups. Of the spermatozoa collected by electroejaculation, 70.6 +/- 3.3% and 75.9 +/- 4.4% were morphologically abnormal in the captive "North American" and in the free-ranging, eastern African populations, respectively. Adrenal activity, as measured by an acute, temporal rise and fall in serum cortisol levels during and after electroejaculation, was no different (p greater than 0.05) between groups. Although serum luteinizing hormone (LH) levels were less (p less than 0.05) in the free-ranging than in the captive animals, serum testosterone concentrations were similar. The data indicate that the comparatively poor reproductive performance of cheetahs maintained in zoological parks is not attributable to a captivity-induced response afflicting the male. Furthermore, there is no evidence that ejaculate/endocrine characteristics differ between the two subspecies. Because adrenal/gonadal activity and the number of pleiomorphic spermatozoa are similar between the test groups, the results suggest that spermatozoal diversity originates as a result of the extreme genetic monomorphism observed universally in the species. 相似文献
6.
物种的分布变化是衡量生物多样性变化的一个重要层面,也是生物多样性变化研究领域备受关注的热点。根据对四川省东南地区6县14个乡镇的访问调查,分析了四川省东南部云豹(Neofelis nebulosa)分布区的变化趋势,并对近10年潜在有无云豹分布的区域在1988年和2017年的景观格局进行对比分析,探讨了四川东南地区云豹分布区变化的原因。结果显示:(1)40年前云豹曾在调查区域广泛分布,近40年来云豹分布范围呈现逐渐缩减的趋势,到近10年潜在有云豹分布的仅3个县3个乡镇;(2)天然阔叶林是云豹适宜的生境,潜在有云豹分布地区阔叶林在近30年里均是面积最大的景观类型,30年间增加了18.13%。潜在无云豹分布地区阔叶林在30年前占比为13.67%,30年间减少了39.29%,其主要景观类型在30年间由农业用地转换为竹林类型;(3)30年间,潜在有无云豹分布地区阔叶林破碎化程度均加剧,而潜在无云豹分布地区的破碎化程度较潜在有云豹分布地区严重;(4)潜在有无云豹分布区域居民野生动物保护意识均不强烈,在潜在无云豹分布区域的保护意识和意愿稍高;(5)本研究认为,早在40年前由于人为捕杀和土地开垦,就导致云豹种群在研究区域内衰退,近30年虽然农业用地大幅转换为竹林使森林总面积增加,但并未对云豹的保护起到积极作用,阔叶林的生境退变则使前期已经衰退的云豹种群分布区持续缩减,以致难觅踪迹。 相似文献
7.
于1997年10月到1999年10月在泰国KhaoYai国家公园对两种同域分布的物种(即豹猫和云豹)进行了研究。使用带诱饵的陷阱捕捉了这些动物,进行麻醉,确定了性别、年龄,并戴上了无线电项圈,对6只雌性豹猫和4只雄性豹猫进行了1—18个月的无线电追踪。豹猫在干旱季节的利用区域大于雨季,雄性利用的区域大于雌性。在夜间和晨昏时节,豹猫活动增加,但是并没有节律性活动。所有豹猫个体在旱季和雨季的活动都相似,但雄性个体的白天活动多于雌性。豹猫的行走距离有性别差异但是没有季节差异;其食物以鼠类为主。分别对1只雌性云豹和1只雄性云豹进行了17个月和7个月的无线电追踪,雌性个体的活动面积为39.4km^2,而雄性个体活动面积为42.2km^2,核心区都是2.9km2。云豹对半绿林的使用大于其它类型的植被,在晨昏和夜间的活动增加,其活动无节律。 相似文献
8.
Directional selection in the evolution of elongated upper canines in clouded leopards and sabre‐toothed cats
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Extremely developed or specialized traits such as the elongated upper canines of extinct sabre‐toothed cats are often not analogous to those of any extant species, which limits our understanding of their evolutionary cause. However, an extant species may have undergone directional selection for a similar extreme phenotype. Among living felids, the clouded leopard, Neofelis nebulosa, has exceptionally long upper canines for its body size. We hypothesized that directional selection generated the elongated upper canines of clouded leopards in a manner similar to the process in extinct sabre‐toothed cats. To test this, we developed an approach that compared the effect of directional selection among lineages in a phylogeny using a simulation of trait evolution and approximate Bayesian computation. This approach was applied to analyse the evolution of upper canine length in the Felidae phylogeny. Our analyses consistently showed directional selection favouring longer upper canines in the clouded leopard lineage and a lineage leading to the sabre‐toothed cat with the longest upper canines, Smilodon. Most of our analyses detected an effect of directional selection for longer upper canines in the lineage leading to another sabre‐toothed cat, Homotherium, although this selection may have occurred exclusively in the primitive species. In all the analyses, the clouded leopard and Smilodon lineages showed comparable directional selection. This implies that clouded leopards share a selection advantage with sabre‐toothed cats in having elongated upper canines. 相似文献
9.
Sarah Rouse Pouyan Behnoud Kaveh Hobeali Peyman Moghadas Zolfaghar Salahshour Hossein Eslahi Mousa Ommatmohammadi Ali Khani Abolfazl Shabani David W. Macdonald Mohammad S. Farhadinia 《Ecology and evolution》2021,11(23):16572
Although less studied than interspecific interactions, interactions among members of the same species can influence space use and temporal activity. Using techniques commonly applied to the analysis of interspecific interactions—multispecies occupancy modeling and the analysis of temporal activity patterns—we studied intraspecific interactions within a high‐density population of Persian leopards (Panthera pardus saxicolor) in Tandoureh National Park, northeastern Iran. Using camera‐trap data, we investigated spatiotemporal interactions between male leopards, lone female leopards, and families (cubs/females with cubs). While we hypothesized that male and female leopards would display different temporal activity patterns, we did not predict spatial avoidance between these groups. We also predicted that leopard families would exhibit spatiotemporal avoidance from male leopards due to the risk of infanticide. Contrary to our expectations, we did not find any evidence for spatial or temporal avoidance between leopard families and adult male leopards. Male and lone female leopards exhibited positive pairwise co‐occurrence, consistent with reports of high overlap between male and female leopard home ranges. While a high level of overlap in temporal activity patterns was found between males/lone females and males/families, there was evidence for variation in the proportion of time each leopard group was active in particular periods of the diel cycle. Male leopards showed cathemeral activity, while lone females and families were more active during daylight hours. The application of these techniques to interactions within a species has improved understanding of the ecology and behavior of this endangered solitary carnivore. 相似文献
10.
Brown JL 《Animal reproduction science》2011,124(3-4):155-162
Many felid species are endangered because of destructive human activities. As a result, zoos are being tasked with sustaining genetically healthy populations in case of catastrophic extinctions. Unfortunately, with the exception of a few species, most felids do not reproduce well in captivity. The ability to track reproductive activity via hormones is key to developing successful ex situ breeding programs. Through the development of noninvasive fecal hormone monitoring techniques, a high degree of variability in estrous cycle characteristics has been found to exist across the taxon, including the type of ovulation. For example, although all felids have induced ovulations, the occurrence of spontaneous ovulations varies across species, and even between individuals within a species. Clouded leopards, fishing cats and margays frequently have spontaneous ovulations, whereas these are rarely observed in the cheetah, tigrina and ocelot. There are marked species differences in the impact of season on reproductive function, with some being exquisitely sensitive to photoperiod (e.g., Pallas' cat), some moderately affected (tiger, clouded leopard, snow leopard), and others that are not influenced at all (e.g., ocelot, tigrina, margay, lion, leopard, fishing cat). One of the greatest challenges remaining is overcoming the problems associated with highly variable ovarian responses to ovulation induction therapies used with assisted reproductive procedures, like artificial insemination (AI). Success is relatively high in the cheetah and ocelot, but few pregnancies have resulted after AI in clouded leopard, fishing cat and tiger. Current knowledge of the reproductive physiology of nondomestic felids, including aspects of the anatomy, behavior and ovarian cycles will be presented, and how the rapidly growing endocrine database is aiding ex situ management efforts. 相似文献
11.
In this study, we have reported two direct observations of individuals from a one-male group of proboscis monkeys (Nasalis larvatus) being killed by clouded leopards (Neofelis diardi) in the riverine forest along the Menanggul river, a tributary of the Kinabatangan river in Sabah, Malaysia. One of the two individuals was an infant female and the other was a juvenile female. Based on literature reviews and the observations reported here, we suggest that clouded leopard and crocodile might be significant potential predators of proboscis monkeys of any age or sex and that predation threats elicit the monkeys' anti-predator strategies. Moreover, the observations of the monkeys' behaviour when the group is attacked by a predator suggest that the adult males in one-male groups play an important role as protectors. 相似文献
12.
Wilting A Christiansen P Kitchener AC Kemp YJ Ambu L Fickel J 《Molecular phylogenetics and evolution》2011,58(2):317-328
Recent morphological and molecular studies led to the recognition of two extant species of clouded leopards; Neofelis nebulosa from mainland southeast Asia and Neofelis diardi from the Sunda Islands of Borneo and Sumatra, including the Batu Islands. In addition to these new species-level distinctions, preliminary molecular data suggested a genetic substructure that separates Bornean and Sumatran clouded leopards, indicating the possibility of two subspecies of N. diardi. This suggestion was based on an analysis of only three Sumatran and seven Bornean individuals. Accordingly, in this study we re-evaluated this proposed subspecies differentiation using additional molecular (mainly historical) samples of eight Bornean and 13 Sumatran clouded leopards; a craniometric analysis of 28 specimens; and examination of pelage morphology of 20 museum specimens and of photographs of 12 wild camera-trapped animals. Molecular (mtDNA and microsatellite loci), craniomandibular and dental analyses strongly support the differentiation of Bornean and Sumatran clouded leopards, but pelage characteristics fail to separate them completely, most probably owing to small sample sizes, but it may also reflect habitat similarities between the two islands and their recent divergence. However, some provisional discriminating pelage characters are presented that need further testing. According to our estimates both populations diverged from each other during the Middle to Late Pleistocene (between 400 and 120 kyr). We present a discussion on the evolutionary history of Neofelis diardi sspp. on the Sunda Shelf, a revised taxonomy for the Sunda clouded leopard, N. diardi, and formally describe the Bornean subspecies, Neofelis diardi borneensis, including the designation of a holotype (BM.3.4.9.2 from Baram, Sarawak) in accordance with the rules of the International Code of Zoological Nomenclature. 相似文献
13.
Buckley-Beason VA Johnson WE Nash WG Stanyon R Menninger JC Driscoll CA Howard J Bush M Page JE Roelke ME Stone G Martelli PP Wen C Ling L Duraisingam RK Lam PV O'Brien SJ 《Current biology : CB》2006,16(23):2371-2376
Among the 37 living species of Felidae, the clouded leopard (Neofelis nebulosa) is generally classified as a monotypic genus basal to the Panthera lineage of great cats. This secretive, mid-sized (16-23 kg) carnivore, now severely endangered, is traditionally subdivided into four southeast Asian subspecies (Figure 1A). We used molecular genetic methods to re-evaluate subspecies partitions and to quantify patterns of population genetic variation among 109 clouded leopards of known geographic origin (Figure 1A, Tables S1 ans S2 in the Supplemental Data available online). We found strong phylogeographic monophyly and large genetic distances between N. n. nebulosa (mainland) and N. n. diardi (Borneo; n = 3 individuals) with mtDNA (771 bp), nuclear DNA (3100 bp), and 51 microsatellite loci. Thirty-six fixed mitochondrial and nuclear nucleotide differences and 20 microsatellite loci with nonoverlapping allele-size ranges distinguished N. n. nebulosa from N. n. diardi. Along with fixed subspecies-specific chromosomal differences, this degree of differentiation is equivalent to, or greater than, comparable measures among five recognized Panthera species (lion, tiger, leopard, jaguar, and snow leopard). These distinctions increase the urgency of clouded leopard conservation efforts, and if affirmed by morphological analysis and wider sampling of N. n. diardi in Borneo and Sumatra, would support reclassification of N. n. diardi as a new species (Neofelis diardi). 相似文献
14.
Goeritz F Quest M Wagener A Fassbender M Broich A Hildebrandt TB Hofmann RR Blottner S 《Theriogenology》2003,59(7):1487-1502
Roe deer are seasonal breeders with a short rutting season from mid-July to mid-August. The seasonality of reproductive activity in males is associated with cyclic changes between growth and involution of both testes and the accessory sex glands. This study characterizes morphological and functional parameters of these organs prior to, during and after breeding season in live adult roe deer bucks. Size and morphology of the reproductive tract was monitored monthly by transcutaneous (testes, epididymis) and transrectal (accessory glands) ultrasonography. Semen was collected by electroejaculation. Concentration, motility and morphological integrity of spermatozoa as well as the content of proteins and testosterone in semen plasma were evaluated. Proportions of haploid, diploid and tetraploid cells were estimated by flow cytometry in testicular tissue biopsies. Serum testosterone was measured by enzyme immunoassay. Most parts of the male reproductive tract showed distinct circannual changes in size and texture. These changes were most pronounced in the testes, seminal vesicles, and prostate. All reproductive organs were highly developed during the rut only. The volume of ejaculates, total sperm number and percentages of motile and intact spermatozoa also showed a maximum during this period and corresponded with high proportions of haploid cells in the testis. The highest percentages of tetraploid cells were found in the prerutting period. The production of motile and intact spermatozoa correlated with both the protein content of semen plasma and the concentration of testosterone in semen plasma and blood serum. These results suggest the importance of combined actions of the testes and accessory sex glands and the crucial role of testosterone in facilitating the optimal timing of intensified semen production to ensure sufficient numbers of normal spermatozoa in seasonal breeders. 相似文献
15.
In mammals, reproductive performance is usually associated with seasons. Chinchilla lanigera, an endemic South American rodent, reproduces throughout the year in captivity but its seasonal breeding pattern is not fully understood. The present study was designed to evaluate (bi-weekly) over 1 year: (1) testicular volume variations and (2) seminal volume, sperm concentration and functional activity changes. Five animals were studied; they were individually housed indoors (22.2 +/- 1.0 degrees C) under natural photoperiod in Argentina (Córdoba, 31 degrees S-64 degrees W). Semen was obtained by electroejaculation; a total of 116 ejaculates was evaluated. Monthly values for paired testicular volume were less in the middle of the summer than in other seasons (p < 0.006), while those for seminal volume and total spermatozoa/ejaculate were not significantly different; these variables ranged between 7.2-30.9 cm(3), 10-130 microL and 0.9-432.6 x 10(6), respectively. Spermatozoa concentration was (x 10(6)/mL) 2145.9 +/- 365.3 and the pH of semen was 7.3 +/- 0.0. Spermatozoa functional activity showed no significant differences between monthly evaluations; confidence intervals were calculated for the means of: motility, 92.2-95.8%; viability, 92.2-96.1%; swollen cells (hypo-osmotic swelling test), 81.2-87.7% and viable intact acrosome, 83.5-89.0%. The present study represents the first longitudinal reproductive assessment in the chinchilla male. In conclusion, males produce spermatozoa continuously that exhibit high quality functional activity. 相似文献
16.
17.
JoGayle Howard Ann P. Byers Janine L. Brown Sean J. Barrett Margit Z. Evans Rick J. Schwartz David E. Wildt 《Zoo biology》1996,15(1):55-69
Exogenous gonadotropins and a laparoscopic intrauterine artificial insemination (AI) technique were assessed for effectiveness in the clouded leopard (Neofelis nebulosa), a species difficult to breed in captivity due to severe mate incompatibility. Fourteen hormone trials using 10 female clouded leopards were performed to evaluate the ability of 50, 100, or 200 i.u. pregnant mares' serum gonadotropin (PMSG) and 75 or 100 i.u. human chorionic gonadotropin (hCG) to induce folliculogenesis and ovulation, respectively. Laparoscopic evaluation of ovarian activity was conducted at 29–48 hr after hCG administration. Time of ovulation in PMSG/hCG-treated clouded leopards was approximately 38–39 hr after hCG. Excessive follicular development was observed using the high hormone dosages (200 i.u. PMSG/100 i.u. hCG), whereas the lower dosages avoided ovarian hyperstimulation. Previous ovulation sites and mature corpora lutea were detected upon laparoscopic examinations in two of the 10 females housed alone, indicating that this species occasionally spontaneously ovulates. Five females were inseminated by depositing electroejaculated, washed sperm transabdominally into the proximal aspect of each uterine horn. One postovulatory female, previously treated with 100 i.u. PMSG and 75 i.u. hCG and inseminated in utero with 88 × 106 motile sperm at 45 hr post-hCG, produced a pregnancy and two live cubs after an 89 day gestation. These results demonstrate: (1) an exquisite ovarian sensitivity to exogenous gonadotropins in clouded leopards; and (2) that artificial insemination has the potential of resulting in offspring in this species. (This article is a US Government work and, as such, is in the public domain in the United States of America.) © 1996 Wiley-Liss, Inc. 相似文献
18.
L. V. Osadchuk 《Russian Journal of Developmental Biology》2010,41(3):176-182
The formation of generative function in pubescence is studied in males of three inbred mice lines BALB/cLac, CBA/Lac, and
PT. From days 35 through 60 of life every 5 days the amount of sperm cells and the quantity of abnormal heads of spermatozoa
in males are calculated in both epididymises and the morphometry of the testicles, epididymises, and seminal vesicles is carried
out. Interlinear deviations in the pubertal dynamics of the parameters of spermatogenesis and the morphometric indexes are
determined, indicating a weak spermatogenesis process in males of CBA/Lac in comparison with males from the other lines. Males
from the line CBA/Lac are characterized by a low amount of epididymal spermatozoa combined with low frequency of abnormal
spermatozoon heads; these traits can be considered as a compensatory process that increases fertility. By the end of the period,
i.e., on days 55–60 of life, the males of all three inbred mice lines have not reached the definitive level in the number
of epididymal spermatozoa; the weight of the testicles, epididymise, and seminal vesicles; and body weight. Thus, in laboratory
mice, the beginning of reproductive activity is not connected with these reproductive indexes reaching the definitive level.
The results of the study show that in adult mature males of laboratory mice the interlinear deviations in generative function
emerge in the pubertal period and persist thereafter. 相似文献
19.
S. Miththapala J. Seidensticker L. G. Phillips K. L. Goodrowe S. B. U. Fernando L. Forman S. J. O'brien 《Zoo biology》1991,10(2):139-146
Electrophoretic variation of 50 gene-enzyme systems was typed in a population of 33 captive leopards (Panthera pardus) from the island of Sri Lanka. The captive leopard population was composed of several lineages: (1) wild-caught leopards of the island subspecies (P. p. kotiya), (2) captive-born animals of the same subspecies, (3) a melanistic lineage whose founders were obtained from Malaysia (P. p. delacouri), and (4) leopards of known mixed lineage and unknown status. Two loci, APRT and PGD, were polymorphic in all samples, whereas 48 loci were invariant. Percent polymorphism (P) and percent average heterozygosity (H) were calculated as 4% and 1.4%, respectively, for the wild-caught leopards; 4% and 1.2% for the captive-born kotiya leopards; and 4% and 2.0% for the melanistic lineage. The overall results revealed a detectable decrease in genetic variability compared with a previous study of captive leopards from mainland origins. The mainland leopards had three additional polymorphic loci, ADA, ESI, and HBB. Reexamination of the TF locus using a revised protocol resolved a new allele in the sample of mainland leopards but not in the Sri Lankan sample. With this new polymorphism, recalculated P and H values for the mainland sample are 10% and 3.1%, respectively. No significant differences in polymorphic loci were observed between the leopard subspecies examined. 相似文献
20.
M. Yoneda ¶ M. Tokimura † H. Fujita ‡ N. Takeshita K. Takeshita M. Matsuyama S. Matsuura 《Journal of fish biology》1998,53(1):164-178
The reproductive cycle and sexual maturity of the anglerfish Lophiomus setigerus were examined. Spermatids were released from the germinal cysts into the lumina of the seminal lobules, and both spermatids and spermatozoa were present in the lumina of the seminal lobules and sperm ducts. Spermatogenesis and vitellogenesis occurred throughout most of the year. The testes of males were full of spermatozoa throughout the year, with spawning from May to November. Males and females reached sexual maturity at a mean total length and age of 178 mm, 3.3 years and 303 mm, 6.1 years, respectively. There were clear seasonal cycles in the gonadosomatic index (IG ) and hepatosomatic index ( I H ) in females. The mean IG of females increased rapidly with ovarian development while the mean I H decreased from the middle of vitellogenesis to final maturation. Mean values of I G and I H in males increased with testicular development. 相似文献