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Search Results: 1 - 6 of 6 matches for " Lancelet "
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Ultrastructure and function of follicle cell in the ovary ofBranchiostoma belcheri
Ulrich Welsch,Yongqiang Fang
Science China Life Sciences , 1997, DOI: 10.1007/BF02879108
Abstract: The ultrastructure of follicle cells in the ovary at different developmental stages ofBranchiostoma has been observed in detail with a transmission electron microscope. The results indicate that only one kind of follicle cell exists with structural features related to steroid hormone biosynthesis: (i) oval or round mitochondria with tubules; (ii) smooth surfaced endoplasmic reticulum; (iii) several large lipid droplets in the cytoplasm; (iv) a well developed Golgi complex and tubular rough surfaced endoplasmic reticulum, as can be found in mammalian theca interna cells. In addition, as steroid hormone synthesizing cells, they obviously play an important role in the phagocytosis of relict gametes and cellular debris and may have a nutritive function for the oocytes. They can produce abundant secretory granules in stages III-IV ovaries. In mature ovaries they transform into flat epithelial cells with numerous microfilaments which may play a role in ovulation.
A neurochemical map of the developing amphioxus nervous system
Simona Candiani, Luca Moronti, Paola Ramoino, Michael Schubert, Mario Pestarino
BMC Neuroscience , 2012, DOI: 10.1186/1471-2202-13-59
Abstract: By single and double in situ hybridization experiments, we identified glutamatergic, GABAergic/glycinergic, serotonergic and cholinergic neurons in developing amphioxus. In addition to characterizing the distribution of excitatory and inhibitory neurons in the developing amphioxus CNS, we observed that cholinergic and GABAergic/glycinergic neurons are segmentally arranged in the hindbrain, whereas serotonergic, glutamatergic and dopaminergic neurons are restricted to specific regions of the cerebral vesicle and the hindbrain. We were further able to identify discrete groups of GABAergic and glutamatergic interneurons and cholinergic motoneurons at the level of the primary motor center (PMC), the major integrative center of sensory and motor stimuli of the amphioxus nerve cord.In this study, we assessed neuronal differentiation in the developing amphioxus nervous system and compiled the first neurochemical map of the amphioxus CNS. This map is a first step towards a full characterization of the neurotransmitter signature of previously described nerve cell types in the amphioxus CNS, such as motoneurons and interneurons.
Ultrastructure and function of follicle cell in the ovary of Branchiostoma belcheri

Ulrich WelschFANG Yongqiang,

中国科学C辑(英文版) , 1997,
Abstract: The ultrastructure of follicle cells in the ovary at different developmental stages ofBranchiostoma has been observed in detail with a transmission electron microscope. The results indicate that only one kind of follicle cell exists with structural features related to steroid hormone biosynthesis: (i) oval or round mitochondria with tubules; (ii) smooth surfaced endoplasmic reticulum; (iii) several large lipid droplets in the cytoplasm; (iv) a well developed Golgi complex and tubular rough surfaced endoplasmic reticulum, as can be found in mammalian theca interna cells. In addition, as steroid hormone synthesizing cells, they obviously play an important role in the phagocytosis of relict gametes and cellular debris and may have a nutritive function for the oocytes. They can produce abundant secretory granules in stages III-IV ovaries. In mature ovaries they transform into flat epithelial cells with numerous microfilaments which may play a role in ovulation.
Position in the evolution of reproductive endocrine of amphioxus,Branchiostoma belcheri
Yongqiang Fang
Chinese Science Bulletin , 1998, DOI: 10.1007/BF02898905
Abstract: This review summarizes the recent discoveries of many authors who found that in amphioxus Hatschek’s pit is capable of synthesizing vertebrate gonadotropin-like substance, and that the content of gonadotropin-releasing hormone in the amphioxus’ body shows a positive correlation with the reproductive cycle, and that the sex steroid hormone exists in gonads. Exogenous hormones could promote gonadal development, maturation and reproductive activity in amphioxus. A possible implication might be that the reproductive activity in amphioxus is regulated by reproductive hormones like vertebrate, indicating the existence of primitive reproductive endocrine regulatory axis, brain vesicle-Hatschek’s pit-gonads axis, as compared with regulatory axis of vertebrate. It will provide a new line for establishing the position of reproductive endocrine evolution in lancelet.
Position in the evolution of reproductive endocrine of amphioxus, Branchiostoma belcheri

Yongqiang Fang,

科学通报(英文版) , 1998,
Abstract: This review summarizes the recent discoveries of many authors who found that in amphioxus Hatschek’s pit is capable of synthesizing vertebrate gonadotropin-like substance, and that the content of gonadotropin-releasing hormone in the amphioxus’ body shows a positive correlation with the reproductive cycle, and that the sex steroid hormone exists in gonads. Exogenous hormones could promote gonadal development, maturation and reproductive activity in amphioxus. A possible implication might be that the reproductive activity in amphioxus is regulated by reproductive hormones like vertebrate, indicating the existence of primitive reproductive endocrine regulatory axis, brain vesicle-Hatschek’s pit-gonads axis, as compared with regulatory axis of vertebrate. It will provide a new line for establishing the position of reproductive endocrine evolution in lancelet.
Preliminary analysis of the feeding habits of amphioxus, Branchiostoma belcheri (Grey), found at Naozhou Island of Zhanjiang
湛江硇洲岛文昌鱼(Branchiostoma belcheri)的食性研究

YAN Yun-rong,LU Huo-sheng,BAI Xiu-juan,ZHAO Hao-bo,LIAO Chuan-yi,
颜云榕
,卢伙胜,白秀娟,赵浩波,廖传翼

海洋科学 , 2010,
Abstract: This paper described the observations and analysis of the stomach content of amphioxus regarding to spring and summer season, gender and body length. The samples were captured by special device, with a cross-section of 0.075m2, at the Naozhou Island Sea area outside Zhanjiang City from April to July of 2006. Food residue found in the alimentary canal of the amphioxus was mainly made up of mud and sand debris. In addition, Thirty-four species of organism were identified, including benthic diatom, at a percentage of 58.8%, as well as a few dinophyta, lamellibranch larva, copepods larva, and protozoa. The feeding habits of amphioxus were not the same, and the occurrence of its food materials was also different in spring and summer. The feeding habits of amphioxus were similar between different genders. The lancelets began to take animal food when they were mature.
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