Reproductive cycle and sperm storage of female coral snakes, Micrurus corallinus and Micrurus frontalis

2020 ◽  
Vol 41 (1) ◽  
pp. 13-27 ◽  
Author(s):  
Erick Augusto Bassi ◽  
Rafaela Zani Coeti ◽  
Selma Maria de Almeida-Santos

Abstract We analyzed the hypothesis that the lack of synchronization between the mating and ovulation period of Micrurus frontalis (BRT clade) is indicative of the capacity of females to store sperm. Conversely, since these reproductive events occur in the same season for Micrurus corallinus (BRM clade), sperm storage is not expected. Thus, we analyzed the reproductive cycle of female M. corallinus and M. frontalis, and investigated the occurrence of sperm storage. Our results showed that these two species of coral snakes (clades BRM and BRT) possess different reproductive cycles. Micrurus frontalis exhibits an extensive reproductive period encompassing three seasons (summer, autumn and winter), while M. corallinus directs secondary vitellogenesis and ovulation to the hottest period of the year (spring and summer). We confirm, for the first time, the strategy of sperm storage (SSr) in females of the genus Micrurus. We observed sperm storage receptacles located in the non-glandular uterus in all seasons of the year for M. corallinus and in spring, summer and autumn in M. frontalis. Furthermore, the presence of SSr in females in the non-reproductive (post-ovulatory) period, the verification of myoid cells around the receptacles and secretion of neutral carbohydrates in the lumina of SSrs may indicates a long-term storage. The posterior infundibulum is another possible region of sperm storage by the presence of tubular ciliated gland; however, reproductive studies with other species of the genus are necessary for a better understanding of the reproductive strategies of the BRT and BRM clades.

2017 ◽  
Vol 107 (3) ◽  
pp. 362-368 ◽  
Author(s):  
Wayne M. Jurick ◽  
Otilia Macarisin ◽  
Verneta L. Gaskins ◽  
Eunhee Park ◽  
Jiujiang Yu ◽  
...  

Botrytis cinerea causes gray mold and is an economically important postharvest pathogen of fruit, vegetables, and ornamentals. Fludioxonil-sensitive B. cinerea isolates were collected in 2011 and 2013 from commercial storage in Pennsylvania. Eight isolates had values for effective concentrations for inhibiting 50% of mycelial growth of 0.0004 to 0.0038 μg/ml for fludioxonil and were dual resistant to pyrimethanil and thiabendazole. Resistance was generated in vitro, following exposure to a sublethal dose of fludioxonil, in seven of eight dual-resistant B. cinerea isolates. Three vigorously growing B. cinerea isolates with multiresistance to postharvest fungicides were further characterized and found to be osmosensitive and retained resistance in the absence of selection pressure. A representative multiresistant B. cinerea strain caused decay on apple fruit treated with postharvest fungicides, which confirmed the in vitro results. The R632I mutation in the Mrr1 gene, associated with fludioxonil resistance in B. cinerea, was not detected in multipostharvest fungicide-resistant B. cinerea isolates, suggesting that the fungus may be using additional mechanisms to mediate resistance. Results from this study show for the first time that B. cinerea with dual resistance to pyrimethanil and thiabendazole can also rapidly develop resistance to fludioxonil, which may pose control challenges in the packinghouse environment and during long-term storage.


2020 ◽  
Vol 26 (3) ◽  
pp. 542-550
Author(s):  
Imran Tarique ◽  
Mansoor Tariq ◽  
Xuebing Bai ◽  
Qu Wenjia ◽  
Ping Yang ◽  
...  

AbstractPost-testicular maturation of spermatozoa is crucial for attaining the morphological and functional capabilities needed for successful fertilization. Epididymal epithelia offer a favorable environment for spermatozoa that are stored long term in the turtle epididymis; however, sperm–epithelial interactions during storage, which are enormously important for sperm functional and morphological maturation, are still largely unknown in turtles. The present study examined the epididymis during the sperm-storage period (November–April) in the Chinese soft-shelled turtle (Pelodiscus sinensis). Light and transmission electron microscopy were used to determine the cellular features of each epididymal segment (caput, corpus, and cauda) and their epithelial interactions with the spermatozoa. Spermatozoa were mainly located in the lumena of caput, corpus, and cauda epididymides. Numerous spermatozoa were bound to apical surfaces of the epithelia, and several were even embedded in the epithelial cytoplasm of the caput and corpus epididymides. No embedded spermatozoa were found in the cauda epididymis. In all epididymal segments, principal and clear cells showed the synthetic activity, evidenced by a well-developed endoplasmic reticulum network and high and low electron-dense secretory materials, respectively. Principal and clear cells in the caput and corpus segments showed embedded spermatozoa in electron-dense secretions and in the lipid droplets within the cytoplasm. No lysosomes were observed around the embedded spermatozoa. The lumena of the caput and corpus segments showed few apocrine and low electron density secretions. In the lumen of the cauda epididymidis, different secretions, such as holocrine with low and high electron density and their fragmentation, apocrine, and dictyosome, were found and are summarized. Altogether, sperm physical interactions with secretions either in the cytoplasm of epithelium or in the lumen may support the viability, morphological maintenance, and transfer of various proteins involved in long-term sperm storage in the turtle. This interaction could help us to understand the mechanisms of long-term sperm storage and provide more insights into the reproductive strategies of turtle sperm preservation.


2009 ◽  
Vol 21 (1) ◽  
pp. 180 ◽  
Author(s):  
C. Morrow ◽  
S. Kudeweh ◽  
M. Goold ◽  
S. Standley

In 1999, the New Zealand captive population of Southern white rhinoceros (Ceratotherium simum simum) was increased with the addition of six wild-caught founders. We report on the breeding success of two females (est. 5 to 6 years at import) and a female born in 2000 (conceived in the wild). Fecal samples were collected 1 to 3 times per week from females (n = 3) for several periods (5 to 24 months) between 2000 and 2008. Reproductive cycles and pregnancy were characterized using fecal progestogen concentrations, observations of courtship behaviour and parturition dates. The average length of the reproductive cycle was 31.6 ± 0.6 days (range 26–38 days, n = 34 cycles). Four pregnancies were confirmed in one female with a sex ratio of 1 female to 3 males (including 1 male loss at an estimated 5 months of gestation), known gestation lengths were 514 and 507 days. In the non-reproducing adult female, long cycles (67.2 ± 1.3 days, n = 5) were detected in addition to regular cycles (31.9 ± 0.9 days, n = 13) during the first 3 years in captivity, consistent with previous reports (Schwarzenberger F et al. 1998 An. Repro. Sci. 53, 173–190; Brown JL et al. 2001 Zoo Biol. 20, 463–486). The absence of breeding behavior and low progestogen concentrations for an extended 4-year period was cause for concern for the Australasian Species Management Programme managers (Hermes R et al. 2004 An. Repro. Sci. 82–83, 49–60; Hermes R et al. 2006 Theriogenology 65, 1492–1515). In 2007, the social structure of the Hamilton Zoo rhinoceros group was altered by exchanging the breeding male and two male offspring for a wild-caught male from Auckland Zoo. Within two months of arrival the long-term acyclic female had resumed cycling and had conceived six months after introduction of the new male. The young captive-born female continued to have regular length cycles and mating was observed with the new male. Recently, early embryonic loss was determined by ultrasound in the young female having a long 70 day cycle determined by fecal analysis. Fecal progestogen concentrations were useful for diagnosing pregnancy after 3 months gestation with concentrations four times higher than luteal phase concentrations by 9 to 12 weeks after mating (n = 3). Two females exhibited seasonal acyclic periods characterized by low progestogen concentrations corresponding to decreasing daylength (autumn and winter months). Fecal progestogen monitoring of reproductive status and pregnancy combined with behaviour observations has provided valuable information for breeding management decisions and planning for parturition in this population. The reversal of long-term acyclicity and a resulting pregnancy that represents two original founders is particularly significant for the genetic diversity of the Australasian population of white rhinoceros.


2020 ◽  
Vol 176 ◽  
pp. 03021
Author(s):  
Natalia Zavorokhina ◽  
Natalia Pankratyeva ◽  
Nadezhda Goncharova

Nowadays in the context of innovative development the bread intended for long-term storage is necessary in hard-to-reach areas of Sverdlovsk region, participants of expeditions, workers of logging, geological parties, etc. Taking into account the constant demand for such products, it is necessary to develop new approaches to their creation.The aim of the study was the development of long-term storage bread from wheat flour, preserving consumer characteristics throughout the shelf life.The synergism of betulin,nisin and ascorbic acid was studied for the first time when they are used together to inhibit potato bread disease (hereinafter CBH). It is proved that the use of additives, including 0.015% nisin together with 0.005% betulin to the mass of flour increases the shelf life of wheat bread up to 7 days since betulin inhibits CBH, nisin inhibits the development of mold under pH conditions in the range of 5.5-6.5.For the first time, a technique is proposed for producing betulin nanosuspension with a high degree of dispersion. The effect of betulin nanosuspension with emulsifiers of calcium lactylate, polyglycerol fatty acid esters, lecithin on the inhibition of CBH and an increase in the shelf life of wheat bread was studied.


2017 ◽  
Vol 2 (1) ◽  
Author(s):  
Abilio Alvaro ◽  
Maria I. Andrade ◽  
Godwill S. Makunde ◽  
Fishua Dango ◽  
Omowumi Idowu ◽  
...  

AbstractLong-term storage of sweetpotato roots is a great challenge for smallholder farmers in Mozambique. Piecemeal harvesting allows several months supply of roots for household consumption provided weevil infestation is avoided. The objectives of the present studies were to determine yield and changes in key macro- and micronutrients associated with early or late harvesting of orange-fleshed sweetpotato cultivars in Mozambique. Four trials representing harvesting periods of 3, 4, 5 or 6 months after planting were established at Gurue in 2015. The randomized complete block design with three replications was laid in each trial. Yield measurements were done in the field and samples were selected and scanned for dry matter, beta-carotene, iron, zinc and carbohydrate using Near Infrared Spectrometry. Collected data were statistically analysed (SAS 1997 software). Yield, dry matter, starch, iron and beta-carotene increased linearly in some cultivars as time to harvest was prolonged. Iron was not affected by harvesting period. Stability of micronutrients such as iron, zinc and beta-carotene is essential when piecemeal harvesting. The study allowed accurate grouping of the cultivars tested into maturity groups for the first time.


2004 ◽  
Vol 824 ◽  
Author(s):  
Boris E. Burakov ◽  
Maria A. Yagovkina ◽  
Vladimir M. Garbuzov ◽  
Alexander A. Kitsay ◽  
Vladimir A. Zirlin

AbstractTo investigate the behavior of monazite during accelerated radiation damage, which simulates effects of long term storage, 238Pu-doped polycrystalline samples of (La,Pu)PO4 and PuPO4 were synthesized for the first time ever and studied using powder X-ray diffraction (XRD) analysis and optical microscopy. The starting precursor materials were obtained by precipitation of La and (or) Pu from their aqueous nitrate solutions followed by calcination in air at 700°C for 1 hour, cold pressing, and sintering in air at 1200-1250°C for 2 hours. The 238Pu contents in ceramic samples measured using gamma spectrometry were (in wt.% el.): 8.1 for (La,Pu)PO4 and 7.2 for PuPO4. The (La,Pu)PO4 monazite remained crystalline at ambient temperature up to a cumulative dose of 1.19 × 1025 alpha decays/m3. In contrast, the PuPO4 monazite became nearly completely amorphous at a relatively low dose of 4.2 × 1024 alpha decays/m3. Swelling and crack formation due to the alpha decay damage was observed in the PuPO4 ceramic. Also, under self-irradiation this sample completely changed color from initial deep blue to black. The (La,Pu)PO4 monazite was characterized by a similar change in color from initial light blue to gray, however, no swelling or crack formation have so far been observed. The results of this study allow us to conclude that the radiation damage behavior of monazite strictly depends on the chemical composition. The justification of monazite-based ceramics as actinide waste forms requires additional investigation.


2013 ◽  
Vol 15 (2) ◽  
pp. 313 ◽  
Author(s):  
C. PORCU ◽  
M. F. MARONGIU ◽  
M. C. FOLLESA ◽  
A. BELLODI ◽  
A. MULAS ◽  
...  

In this paper, the reproductive biology of the velvet belly lanternshark Etmopterus spinax was analyzed in Sardinian waters (central western Mediterranean). This species was sexually dimorphic with females growing to a larger size than males. Marked sexual dimorphism in size was also observed along the vertical gradient. Histological analysis of gonads was very useful in assigning macroscopical maturity stages. The investigation on the microstructure of oviducal gland (OG) highlighted four morphofunctional zones with mucous and/or proteic secretions according to the zone and to their specific functions and development. Sperm in the OG was found for the first time in E. spinax. The localization of sperm storage tubules deeper in OG suggested long-term sperm storage, which is in agreement with the long reproductive cycle described. This species matured late, specifically at 80.7% and 79% at the maximum observed size for females and males respectively. Mature specimens were found throughout the year with pregnant females observed in winter and autumn. A low fecundity was observed with a mean ovarian fecundity of 16.5 mature follicles.


Author(s):  
P. J. W. Olive

Eulalia viridis (L.) is one of a group of polychaete species which are being used in an experimental analysis of the regulation of gametogenesis and reproduction. The back-ground to these studies and some of the preliminary results have been discussed recently by Olive (1980). Despite the abundant data demonstrating the frequent occurrence of well-defined reproductive cycles in marine invertebrates and observations on the correlations between reproductive events and environmental conditions, the mechanisms by which the reproductive cycles of individual species are controlled are very poorly understood. It has generally been accepted since the publication of the important paper of Orton (1920) that the temperature cycle in temperate and boreal regions plays an important role in determining the reproductive cycle, but the nature of the control mechanism is not, in general, understood and is likely to vary markedly between species. Environ-mental conditions such as relative daylength or biological factors such as the quantity and identity of the phytoplankton organisms (Himmelman, 1978, 1979) could also play important roles in regulating the sequence of cellular events which culminates in successful reproduction. These general problems have been discussed by Giese (1959) and more recently by Barnes (1975), Giese & Pearse (1975) and specifically in relation to Polychaeta by Clark (1979) and Olive (1980).


2021 ◽  
Vol 51 (2) ◽  
pp. 113-121
Author(s):  
Ícaro ANTONIO ◽  
Ana SOUSA ◽  
Tiago LENZ ◽  
Izabel FUNO ◽  
Rodolf LOPES ◽  
...  

ABSTRACT This study aimed to establish the reproductive cycle of the mangrove oyster, Crassostrea rhizophorae cultured in the macrotidal estuary of the Paciência River, Maranhão state, on the northeastern coast of Brazil, and its relationship with environmental factors. Oysters were collected monthly throughout 2013 for histological analysis of sex ratio, gonadal development and condition index. The sex ratio was 1:1.39 (M:F) and only 5 specimens presented hermaphroditism. The breeding process was continuous throughout the year and mature (IIIA stage) and spawning oysters (IIIB stage) were present in practically all months. Low variation in temperature seemed to be the main factor for the continuity of the reproductive cycle. Besides temperature, the relationship between rainfall, salinity and primary productivity affected the stimulus and timing of reproductive events. The rainy season, with low values of salinity and high values of chlorophyll a and particulate organic matter, appeared to be the main reproductive period, with release of gametes and production and maturation of new gamete cohorts in the short term. In the tropics, where gamete maturation and release seem to be continuous and concomitant, the condition index does not appear to be the best method to assess reserve accumulation peaks and gonadal repletion.


1999 ◽  
Vol 47 (6) ◽  
pp. 539 ◽  
Author(s):  
Erik Wapstra ◽  
Roy Swain ◽  
Susan M. Jones ◽  
Julianne O'Reilly

We studied the reproductive cycle of two populations of the spotted snow skink, Niveoscincus ocellatus, over a three-year period. This species is widespread in Tasmania and its distribution overlaps those of other species in the genus that show two distinct reproductive strategies: annual reproduction that is completed within one season, and biennial reproduction in which females carry advanced embryos throughout winter hibernation. We chose populations representative of the climatic extremes of the species’ distribution, within these areas of overlap. Niveoscincus ocellatus maintains the same basic reproductive strategy in both populations: summer gestation, primary autumn mating with obligate sperm storage by females, secondary mating in spring, and predominantly spring vitellogenesis and ovulation. In both populations all females reproduce annually, suggesting that reproductive frequency is not constrained by availability of energy. However, we found distinct differences in the timing of ovulation and parturition. Females from our subalpine site ovulated approximately one month later than those from our warmer, lowland site; parturition was delayed by the same period so gestation length was unchanged. The delay in ovulation results in gestation proceeding over the warmest months at the cold site. The annual reproductive cycle of this species appears to constrain its distribution to the lower altitudinal/climatic range of alpine Niveoscincus species. There were minor annual differences in the timing of reproductive events at each site, which we attribute to variation in thermal conditions and the amount of precipitation.


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