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1.
《Journal of morphology》2017,278(12):1739-1753
Patterns of ossification and chondrification are well‐described for several species of turtles, but details of the chondrocranial anatomy are known for only a handful of species. Cleared and double‐stained embryos of Graptemys pseudogeographica were used to examine the fully formed chondrocranium and the formation, chondrification, and ossification of the cranium. The chondrocranium of G. pseudogeographica possesses an unusually large, irregularly shaped foramen epiphaniale that is joined with the fenestra olfactoria. As in other emydids, and many turtles generally, the taenia marginalis is present only as a small projection and the taenia medialis is lacking in mature stages of embryonic development. Ossification data for G. pseudogeographica are consistent with those of other Testudines in that the dentary and maxilla (dermal elements of the upper and lower jaws) ossify early, whereas the articular (an endochondral bone of the lower jaw) ossifies relatively late. Additionally, comparative ossification shows that the vomer is quite variable in its relative timing of ossification across Testudines.  相似文献   

2.
Lauraceae are relatively well-known embryologically and embryological data are available for 23 of about 50 genera. In this paper we present the embryology of Eusideroxylon , an unstudied and key genus within Cryptocaryeae, which are positioned basally in the evolution of Lauraceae, and discuss the evolution of embryological characters in the family. Based on comparisons of over 50 characters, it was found that Eusideroxylon is consistent with Aspidostemon , the core Cryptocaryeae ( Beilschmiedia , Cryptocarya , Endiandra and Potameia ), Caryodaphnopsis and Cassytha in having a glandular anther tapetum. The core Cryptocaryeae further agrees with both Caryodaphnopsis and Cassytha in having an embryo sac protruding from the nucellus. In light of the phylogenetic trees available, both the glandular tapetum and the embryo sac protruding from the nucellus have evolved as homoplasies in Lauraceae, once each in a clade of Cryptocaryeae, and the Caryodaphnopsis and Cassytha clade, respectively. Such character-state distributions suggest that it is better to place both Caryodapnopsis and Cassytha in the same clade as the core Cryptocaryeae. Embryologically, Eusideroxylon appears to have an intermediate state between Hypodaphnis , a genus positioned basal-most in the family, and the core Cryptocaryeae. Supplementary data on the anther and seed of Hypodaphnis are also provided.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 187–201.  相似文献   

3.
【目的】保幼激素(juvenile hormone, JH)在小麦吸浆虫Sitodiplosis mosellana滞育诱导及滞育后静息状态的维持中发挥着重要作用。保幼激素酯酶(hormone esterase, JHE)和保幼激素环氧水解酶(juvenile hormone epoxide hydrolase, JHEH)是调控JH滴度的重要降解酶。本研究旨在探讨JHE和JHEH在小麦吸浆虫滞育和变态发育中潜在功能。【方法】通过RT-PCR和RACE技术从小麦吸浆虫滞育前幼虫克隆JHE和JHEH全长cDNA序列;利用生物信息学软件分析其核苷酸及编码蛋白特性;采用qPCR技术分析其在小麦吸浆虫滞育不同时期(滞育前、滞育期、滞育后静息期和滞育后发育)3龄幼虫及1龄幼虫到成虫不同发育阶段(1-2龄幼虫、预蛹、初蛹、中蛹、后蛹、雌成虫和雄成虫)中的表达水平。【结果】克隆获得了cDNA全长分别为3 102和1 980 bp的小麦吸浆虫SmJHE和SmJHEH基因(GenBank登录号分别为MG876768和MG876769),其开放阅读框分别长1 740和1 371 bp,分别编码579和45...  相似文献   

4.
This investigation aimed to determine the morphological characteristics of the tongue, palate and laryngeal entrance of southern lapwing by gross anatomy and scanning electron microscopy. For this purpose, the organs of three birds were used as material. Numerous densely distributed acicular projections were found on the lingual apex. Papillary crest consisting of sharp conical papillae were observed between the body and root of the tongue. Conical papillae of the lateral border of the papillary crest were triangular in form, and other conical papillae of the papillary crest were shorter in form. There were no papillary projections or papillae on the smooth surfaces of the lingual body and radix. On the median part of the palate, larger conical papillae, which were directed caudally, also surrounded entrance of the choanal cleft. The transversal papillary rows of conical papillae were observed between the rostral and caudal parts of the choanal cleft and on the caudal border of the infundibular cleft. The laryngeal entrance was surrounded by smooth mucosa without conical papillae. However, in the caudal border of the glottic fissure, there was a conical papillary row formed by numerous conical papillae. There were no anatomical differences between female and male birds.  相似文献   

5.
Hoflacher, H. and Bauer, H. 1982. Light acclimation in leaves of the juvenile and adult life phases of ivy (Hedera helix). – Physiol. Plant. 56: 177–182. Light acclimation was investigated during the juvenile and adult life phases of the whole-plant-development in Hedera helix L. For this purpose, cuttings of the juvenile and adult parts of one single parent plant were grown under low-light (PAR 30–50 μmol photons m?2 s?1) and high-light (PAR 300–500 μmol m?2 s?1) conditions: CO2 exchange, chloroplast functions, and specific anatomy of fully developed leaves differentiated under these conditions were determined. In juvenile plants the leaves formed under low and high light had light-saturated rates of net photosynthesis of 6.5 and 11.1 mg CO2 (dm leaf area)?2 h?1, respectively. In adult plants the rates were 9.4 and 22.2 mg dm?2 h?1, indicating a more pronounced capacity for acclimation to strong light in the adult life phase. Higher photosynthetic capacities were accompanied by higher conductances for the CO2 transfer through the stomata, leading to almost the same CO2 concentration in the intercellular spaces. Thus, stomatal conductances were not primarily responsible for the different photo-synthetic capacities. The higher rates in adult and high-light grown leaves were mainly the result of formation of thicker leaves with more chloroplasts per unit leaf area. Expressed per chloroplast, the photosynthetic capacity, the Hill reaction, and the activity of ribulose bisphosphate carboxylase were almost identical in plants grown in low-light and high-light. Measurements of photosynthetic capacity and thickness of leaves of Hedera sampled from field habitats with contrasting light regimes confirm the results of growth chamber studies. It is, therefore, concluded that both life phases of Hedera are capable of acclimating to strong light, but that during the juvenile phase this capacity is not fully developed.  相似文献   

6.
Abstract Photosynthetic and anatomical parameters of leaves from the juvenile and adult part of an ivy plant (Hedera helix L.) have been determined and compared with each other. Light-saturated net photosynthesis (per unit leaf area) was about 1.5 times higher in adult leaves than in juvenile ones. The lower photosynthetic capacity of juvenile leaves was caused by a lower stomatal and especially a lower residual conductance to the CO2-transfer. This corresponds with anatomical features of the leaves, i.e. lower stomatal frequency, fewer chloroplasts per cell, and – most important – thinner leaves, as well as with a less efficient photosynthetic apparatus measured as Hill reaction of isolated broken chloroplasts and activity of ribulose bisphosphate carboxylase. No differences in the respiration in light (relative to net photosynthesis) and in the CO2-compensation concentration could be detected between the two leaf types. These observed anatomical and photosynthetic parameters of the juvenile and adult ivy leaves resemble those reported for shade and sun leaves, respectively, although the leaves investigated originated from the same light environment.  相似文献   

7.
Mating in Platynota stultana resulted in the termination of calling, the gradual reduction of pheromone in the pheromone glands to non-detectable levels (<0.1 ng/♀) within 14 h, and oviposition of the first batch of eggs 20–24 h after copulation. Decapitation of virgin females resulted in a similar decline in pheromone titre, and also eliminated oviposition and calling. Pheromone production appears to be controlled via the head. Mating probably terminates neural or hormonal input required for pheromone production and/or removes neural or hormonal inhibition of pheromone degradation. A juvenile hormone analogue (ZR-512) and juvenile hormones I, II and III applied exogenously to virgin females elicited oviposition comparable to mated females and terminated calling within 48 h. The juvenile hormone analogue also appeared to block pheromone production in virgin females. These results suggest that juvenile hormone may be involved in the switch from virgin to mated behaviour in this species.  相似文献   

8.
Ornithine decarboxylase (ODC) activity was analyzed in Anastrepha fraterculus (Diptera) females (4 days old) submitted to temperature stress (6 degrees C and 20/6 degrees C) and the topical application of juvenile hormone (JH). ODC activity and ejaculatory apodeme measurements (length and width) were made in males (15 days old) after 6 degrees C stress. JH dose of 500 ng and incubation of 3, 7, and 18 h increased ODC activity. Females reared at 6 degrees C and 20/6 degrees C had higher ODC activity than those reared at 25 degrees C. The treatment of 6 degrees C and JH incubation for 1 h increased ODC activity when compared to 6 degrees C treatments only. However, the treatment of 20/6 degrees C only after 3 or 18 h of JH incubation resulted in higher ODC activity than controls (20/6 degrees C) or 20/6 degrees C plus 1 h of JH incubation. Males did not undergo differences in ODC activity when reared at 6 degrees C or 25 degrees C but the ejaculatory apodeme measurements was higher in those reared at 25 degrees C than in those reared at 6 degrees C. The results can be considered an adaptive process to environmental changes.  相似文献   

9.
The objective of this pilot study was to determine if otolith signatures of juvenile summer flounder Paralichthys dentatus (Linnaeus) were differentiable between beach and marsh habitat types within two North Carolina (NC), U.S.A., estuarine systems. Elemental signatures were differentiable between habitats in both systems, and in one system at smaller spatial scales (<5 km) than have been reported for any estuarine species using otolith microchemistry. These results indicate the potential for using summer flounder otolith elemental analysis to assess the nursery role of habitats within NC estuaries.  相似文献   

10.
运用酶解振荡压片技术和常规石蜡切片技术分别研究了无籽八月桔的胚囊育性及无籽八月桔自交和异交(无籽八月桔×台湾椪柑,无籽八月桔×有籽八月桔)的胚胎发育.结果表明:无籽八月桔胚囊可育,成熟胚囊具一个卵细胞、两个助细胞、三个反足细胞以及一个大的含二个极核的中央细胞;其自交和异交的胚胎发育均正常,授粉后2周出现球形胚和少量心形...  相似文献   

11.
The elementary traits and diversity of embryonic setal patterns of 31 species of 22 genera, in three tribes of Hormaphidinae are studied. The embryonic setal patterns to every species are provided. Based on the parsimony principle and the developmental principle, these patterns are analyzed in each tribe following the terminology of Richards (1965). It is suggested that the setal patterns of abdominal tergites are the most important characters in embryonic and adult setal patterns. In conclusion, neoteny is a phylogenetic trend in the Hormaphidinae. Nipponaphidini and Hormaphidini have more typical neoteny in each genus and more diversity in different types of adult viviparous females than Cerataphidini, by showing more frequent and various protopatterns or mesopatterns.  相似文献   

12.
To date, many technologies have been developed to increase efficiency in aquaculture, but very few successful biotechnology molecules have arrived on the market. In this context, marine biotechnology has an opportunity to develop products to improve the output of fish in aquaculture. Published in vivo studies on the action of the pituitary adenylate cyclase‐activating polypeptide (PACAP) in fish are scarce. Recently, our group, for the first time, demonstrated the biological role of this neuropeptide administrated by immersion baths in the growth and development of larval fish. In this work, we have evaluated the effects of recombinant Clarias gariepinus PACAP administration by intraperitoneal injection on growth performance and feeding behavior in juvenile fish. Our results showed the physiological role of this peptide for growth control in fish, including the juvenile stage, and confirm that its biological functions are well conserved in fish, since C. gariepinus PACAP stimulated growth in juvenile tilapia Oreochromis niloticus. In addition, we have observed that the growth‐promoting effect of PACAP in juvenile tilapia was correlated with higher GH concentration in serum. With regard to the neuroendocrine regulation of growth control by PACAP, it was demonstrated that PACAP stimulates food intake in juvenile tilapia. In general, PACAP appears to act in the regulation of the growth control in juvenile fish. These findings propose that PACAP is a prominent target with the potential to stimulate fish growth in aquaculture. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd.  相似文献   

13.
Hiscock  M. J.  Scruton  D. A.  Brown  J. A.  Pennell  C. J. 《Hydrobiologia》2002,483(1-3):161-165
Radiotelemetry was used to investigate the diel activity pattern of juvenile Atlantic salmon (Salmo salar) in early and late winter. Fish were active throughout the diel cycle. However, there was significantly less daytime than nighttime movement and movement declined significantly with increasing fork length. Maximizing winter growth rate, through an overall increase in foraging activity, may reduce the risk of starvation in smaller fish. The results of the present study provide evidence that the activity patterns of juvenile salmonids are quite complex and support the suggestion that individual variation in activity patterns are, at least, partially driven by body size.  相似文献   

14.
In all mammals, growth, development, pregnancy, and lactation increase nutritional demands. Although primate field studies tend to focus on shifts in activity and diet as mechanisms to compensate for these demands, differences in digestive efficiency also are likely to be important. Because the gut microbiota can impact host digestive efficiency, we examined differences in activity budget, diet, and the gut microbial community among adult male (N = 4), adult female (N = 4), and juvenile (N = 5) wild black howler monkeys (Alouatta pigra) across a ten‐month period in Palenque National Park, Mexico to determine how adult females and juveniles compensate for increased nutritional demands. Results indicate that adult females and juveniles consumed more protein and energy than adult males. Adult males, adult females, and juveniles also possessed distinct gut microbial communities, unrelated to diet. Juveniles exhibited a gut microbiota characterized by bacteria from the phylum Firmicutes, such as Roseburia and Ruminococcus, and demonstrated high fecal volatile fatty acid content, suggesting increased microbial contributions to host energy balances. Adult females possessed a higher Firmicutes to Bacteroidetes ratio, also suggesting increased energy production, and their gut microbiota was characterized by Lactococcus, which has been associated with folate biosynthesis. On the basis of these patterns, it appears that the gut microbiota differentially contributes to howler monkey nutrition during reproduction and growth. Determining the nutritional and energetic importance of shifts in activity, diet, and the gut microbiota in other nonhuman primate taxa, as well as humans, will transform our understanding of these life history processes and the role of host‐microbe relationships in primate evolution. Am J Phys Anthropol 155:652–664, 2014. © 2014 Wiley Periodicals, Inc.  相似文献   

15.
Growth rate and energy reserves are important determinants of fitness and are governed by endogenous and exogenous factors. Thus, examining the influence of individual and multiple stressors on growth and energy reserves can help estimate population health under current and future conditions. In young anadromous fishes, freshwater habitat quality determines physiological state and fitness of juveniles emigrating to marine habitats. In this study, the authors tested how temperature and food availability affect survival, growth and energy reserves in juvenile anadromous alewives (Alosa pseudoharengus), a forage fish distributed along the eastern North American continent. Field-collected juvenile anadromous A. pseudoharengus were exposed for 21 days to one of two temperatures (21°C and 25°C) and one of two levels of food rations (1% or 2% tank biomass daily) and compared for differences in final size, fat mass-at-length, lean mass-at-length and energy density. Increased temperature and reduced ration both led to lower growth rates, and the effect of reduced ration was greater at higher temperature. Fat mass-at-length decreased with dry mass, and energy density increased with total length, suggesting size-based endogenous influences on energy reserves. Lower ration also directly decreased fat mass-at-length, lean mass-at-length and energy density. Given the fitness implications of size and energy reserves, temperature and food availability should be considered important indicators of nursery habitat quality and incorporated in A. pseudoharengus life-history models to improve forecasting of population health under climate change.  相似文献   

16.
Quantifying the effect of pollen dispersal and flowering traits on mating success is essential for understanding evolutionary responses to changing environments and establishing strategies for forest tree breeding. This study examined, quantitatively, the effects of male fecundity, interindividual distance and anisotropic pollen dispersal on the mating success of Scots pine (Pinus sylvestris), utilizing a well-mapped Scots pine seed orchard. Paternity analysis of 1021 seeds sampled from 87 trees representing 28 clones showed that 53% of the seeds had at least one potential pollen parent within the orchard. Pronounced variation in paternal contribution was observed among clones. Variations in pollen production explained up to 78% of the variation in mating success, which was 11.2 times greater for clones producing the largest amount of pollen than for clones producing the least pollen. Mating success also varied with intertree distance and direction, which explained up to 28% of the variance. Fertilization between neighboring trees 2.3 m apart was 2.4 times more frequent than between trees 4.6 m apart, and up to 12.4 times higher for trees downwind of the presumed prevailing wind direction than for upwind trees. The effective number of pollen donors recorded in the seed orchard (12.2) was smaller than the theoretical expectation (19.7). Based on the empirical observations, a mating model that best describes the gene dispersal pattern in clonal seed orchards was constructed.  相似文献   

17.
Water strider Aquarius paludum (Fabricius) is a cosmopolitan species colonizes mainly freshwater but occasionally brackish habitats throughout the Palearctic and Oriental regions. Water strider Gerris latiabdominis (Miyamoto) is a common species in Japan lives in temporary habitats as freshwater paddy fields. These two species often occur syntopically. We investigated differences in the developmental response to brackish water during embryonic and larval stages between the two species. Eggs were exposed to 0–1.8% NaCl solutions within 24 h of oviposition. Larvae of G. latiabdominis were exposed to salinities of 0, 0.5%, and 0.9% from the first instar until adult emergence. Limits of NaCl concentration for hatching were 1.3% and 1.0% for A. paludum and G. latiabdominis, respectively. The hatching rate of G. latiabdominis was lower than that of A. paludum at salinities ≥0.9%. The period of embryonic development of G. latiabdominis was more prolonged than that of A. paludum at a given salinity. Although the salinity tolerance of G. latiabdominis was lower than that of A. paludum, our results suggest G. latiabdominis has the physiological capacity to expand into brackish waters. High and low salinity tolerances of A. paludum and G. latiabdominis, respectively, reflect the relatively wide range of habitat salinities utilized by A. paludum and the relatively restricted habitats preferred by G. latiabdominis. The high salinity tolerance of A. paludum could be an important factor contributing to their cosmopolitan distribution because high tolerance to salinity means the possibility of them to be dispersed via ocean or sea to other continents and islands.  相似文献   

18.
19.
and 1992. Ultrastructure and histochemistry of the digestive tract of juvenile Paramphistomum epiclitum (Paramphistomidae: Digenea) during migration in Indian ruminants. International Journal for Parasitology 22: 1089–1101. The digestive tract of juvenile Paramphistomum epiclitum consists of a foregut with a highly muscular terminal pharynx and an oesophagus, which leads to a pair of unbranched and blind-ending intestinal caeca. A syncytium lining the foregut is continuous with the external tegument and displays similar sensory papillae and secretory bodies (T1 and T2). A third type of secretory body (T3) is confined to the oesophageal cytons of newly excysted juveniles and is first evident in the syncytium by day 14 of migration. An epithelium lining the caeca is composed of a single layer of morphologically uniform cells whose apical surface is amplified by microvilli. Dense secretions synthesized in the caecal epithelium of mature cercariae are released during migration by a mechanism resembling modified apocrine discharge. The caecal epithelium of migrating juveniles undergoes a 10-fold increase in surface amplification (irrespective of growth) during its transition from a primarily secretory tissue to one apparently specialized for absorption.  相似文献   

20.
Nutrition utilization and by-product formation in cultured insect cells has been investigated in several insect cells and has been of great interest to cell culturists and physiologists. In this research the biochemical changes in embryonic and fat body primary cultures of silkworm, Bombyx mori, have been compared. TC-100 medium supplemented with 10% and 20% FBS was used in embryonic and fat body primary cultures, respectively. Medium was renewed every week and the amount of glucose, uric acid, urea, total protein and alkaline phosphatase were measured in the samples from medium of primary cultures using spectrophotometeric methods. All biochemical macromolecules except uric acid showed significant changes. Glucose decreased in embryonic tissues, while in fat body culture its amount increased. Urea accumulation in embryonic culture was higher than in the fat body cultures. Since urea is a by-product, this accumulation could be due to higher utilization of amino acids. Total protein showed considerable changes and was consumed by embryonic culture more than the fat body' s. Alkaline phosphatase showed stronger activity in embryonic cells.  相似文献   

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