Embryonic and Postembryonic Development in Bythotrephes cederstroemii

1992 ◽  
Vol 49 (6) ◽  
pp. 1118-1125 ◽  
Author(s):  
Peder M. Yurista
Keyword(s):  
Embryonic Development ◽  
Development Time ◽  
Lake Michigan ◽  
Field Work ◽  
Postembryonic Development ◽  
Complete Life Cycle ◽  
Development Data ◽  
Series Development ◽  
Data Log ◽  
Morphological Series

Laboratory observations were made of embryonic development time for parthenogenic Bythotrephes cederstroemii under differing temperatures spanning the range when Bythotrephes may be present in the plankton of Lake Michigan. Postembryonic development was documented for parthenogenically produced and sexually produced offspring. The complete life cycle of Bythotrephes was observed to have two distinct morphological series. Development time from birth to primaparity, consisting of three instars, was 14.0 ± 1.63 d at 12.7 °C for pathenogenically produced offspring. Development time at 12.7 °C for gametogenically produced offspring was 13.7 ± 1.57 d with four instars. Because parthenogenic eggs released into the brood sac of Bythotrephes do not become obvious until the embryo development is well advanced, a useful model for birth rate calculations in field work was developed based on observable morphological traits of the embryos within the brood sac. A curvilinear logarithmic model of development time (D, hours) as a function of temperature (T degrees Celsius) was fit to the embryonic development data: log (D) = 6.840–7.305log(T) + 2.490log(T)2.

Embryonic development of the newt Triturus italicus in relation to temperature

1998 ◽  
Vol 19 (4) ◽  
pp. 345-355 ◽  
Author(s):  
S. Tripepi ◽  
F. Rossi ◽  
G. Peluso
Keyword(s):  
Embryonic Development ◽  
Development Time ◽  
Normal Development ◽  
Different Temperatures

AbstractThe embryonic development of Triturus italicus was observed at different temperatures. Normal development occurred between 10°C and 22.5°C. In this range of temperatures an hyperbolic relationship between development time and temperature was confirmed.

Clutch size influences embryonic stages at oviposition in a lizard with prolonged egg retention

2017 ◽  
Vol 38 (4) ◽  
pp. 557-561 ◽  
Author(s):  
Thomas Foucart ◽  
Benoit Heulin ◽  
Olivier Lourdais
Keyword(s):  
Body Size ◽  
Embryonic Development ◽  
Clutch Size ◽  
Development Time ◽  
Reproductive Effort ◽  
Resource Limitation ◽  
Egg Retention ◽  
Zootoca Vivipara ◽  
Female Relative ◽  
Clutch Mass

We examined the possible interaction between reproductive effort and embryonic stages at oviposition in oviparous form of the lizard Zootoca vivipara. Our results reveal that the percentage of total embryonic development time (%TEDT) reached at oviposition is negatively correlated to clutch size (adjusted to maternal body size). We found no influence of reproductive burden of female (relative clutch mass, RCM) on %TEDT. The significant effect of fecundity supports the hypothesis that a resource limitation such as oxygen may exist for developing embryos in oviducts. The absence of RCM effect suggests that the available space (abdominal burdening of the mother) does not limit the embryonic stages at oviposition.

scholarly journals MicroRNA and Putative Target Discoveries in Chrysanthemum Polyploidy Breeding

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Fengjiao Zhang ◽  
Jingya Zhao ◽  
Sujuan Xu ◽  
Weimin Fang ◽  
Fadi Chen ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Noncoding Rna ◽  
Target Genes ◽  
Chromosome Doubling ◽  
Postembryonic Development ◽  
Normal Embryo ◽  
Transcriptional Level ◽  
Rna Seq ◽  
Posttranscriptional Level ◽  
Polyploidy Breeding

MicroRNAs (miRNAs), around 22 nucleotides (nt) in length, are a class of endogenous and noncoding RNA molecule that play an essential role in plant development, either by suppressing the transcription of target genes at a transcriptional level or inhibiting translation at a posttranscriptional level. To understand the roles of miRNAs and their target genes in chrysanthemum polyploidy breeding, three sRNA libraries of normal and abnormal embryos after hybridization were performed by RNA-Seq. As a result, a total of 170 miRNAs were identified and there are 41 special miRNAs in cross of paternal chromosome doubling, such as miR169b, miR440, and miR528-5p. miR164c and miR159a were highly expressed in a normal embryo at 18 days after pollination, suggesting the regulatory role at the late stage of embryonic development. miR172c was only detected in the normal embryo at 18 days after pollination, which means that miR172c mainly mediates gene expression in postembryonic development and these genes may promote embryo maturation. Other miRNAs, including miR414, miR2661, and miR5021, may regulate the genes participated in pathways of auxin response and energy metabolism; then they regulate the complex embryonic development together.

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