Degradation of yolk proteins in sea urchin eggs and embryos

Yokota, Yukio; Kato, Koichi

doi:10.1016/0045-6039(88)90071-1

Cited by 60 publications

(38 citation statements)

References 20 publications

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“…The high representation of these three main enzyme classes could be related to particular developmental processes. For instance, some hydrolases (e.g., lysosome acid hydrolases) are known to play an important role in intracellular digestion and synchronic degradation of the major yolk glycoproteins (e.g., vitellins) during early development of sea urchins (Kari, 1985; Yokota & Kato, 1988). Furthermore, some transferases (e.g., glycosyltransferases) are characterized by changes in their activity after fertilization of sea urchin eggs, regulating development by allowing migration of particular groups of cells destined to give rise to the digestive, skeletal, and nervous systems (Evans & Bosmann, 1977).…”

Section: Resultsmentioning

confidence: 99%

Gene expression profiling during the embryo‐to‐larva transition in the giant red sea urchin Mesocentrotus franciscanus

Gaitán‐Espitía

Hofmann

2017

Ecology and Evolution

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In echinoderms, major morphological transitions during early development are attributed to different genetic interactions and changes in global expression patterns that shape the regulatory program for the specification of embryonic territories. In order more thoroughly to understand these biological and molecular processes, we examined the transcriptome structure and expression profiles during the embryo‐to‐larva transition of a keystone species, the giant red sea urchin Mesocentrotus franciscanus. Using a de novo assembly approach, we obtained 176,885 transcripts from which 60,439 (34%) had significant alignments to known proteins. From these transcripts, ~80% were functionally annotated allowing the identification of ~2,600 functional, structural, and regulatory genes involved in developmental process. Analysis of expression profiles between gastrula and pluteus stages of M. franciscanus revealed 791 differentially expressed genes with 251 GO overrepresented terms. For gastrula, up‐regulated GO terms were mainly linked to cell differentiation and signal transduction involved in cell cycle checkpoints. In the pluteus stage, major GO terms were associated with phosphoprotein phosphatase activity, muscle contraction, and olfactory behavior, among others. Our evolutionary comparative analysis revealed that several of these genes and functional pathways are highly conserved among echinoids, holothuroids, and ophiuroids.

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Section: Resultsmentioning

confidence: 99%

Gene expression profiling during the embryo‐to‐larva transition in the giant red sea urchin Mesocentrotus franciscanus

Gaitán‐Espitía

Hofmann

2017

Ecology and Evolution

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“…The yolk platelets are initially neutral, but they become acidic later in development, causing proenzyme maturation and yolk degradation (Fagotto 1991). Yokota & Kato (1988) indicated, for sea urchin eggs and embryos, that the degradation of yolk proteins resulted from the incubation of yolk granules in acidic conditions. Umezawa (1982) presented evidence that the most abundant yolk protein is proteolytically processed primarily by the cathepsin-B-like enzyme.…”

Section: Discussionmentioning

confidence: 99%

Cytological ontogeny of the digestive gland in post-hatching Octopus maya, and cytological background of digestion in juveniles

Martínez¹,

López-Ripoll²,

Avila-Poveda³

et al. 2011

Aquat. Biol.

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The cephalopod digestive gland (DG) is responsible for enzyme production as well as nutrient and lipid storage. Octopus maya (Mollusca: Cephalopoda) is a holobenthic octopus species with aquaculture potential. To develop a balanced food for the rearing of this octopus, it is necessary to understand its digestive physiology. We performed histological studies on the structural change of the DG (cytological ontogeny) associated with age (from 0 to 30 d posthatching, DPH) and food (postprandial change in 120 DPH juveniles). Early ontogeny of DG was defined in 3 stages: (1) yolk platelets stage (0 to 5 DPH), (2) transition stage (6 to 10 DPH) and (3) heterolysosomes (food reserves) stage (>12 DPH). In Stage 1, the DG had anatomically undifferentiated tubules, but was filled with yolk platelets. The tubular structures developed lumen by 5 DPH. Stage 2 (starting at 6 DPH) corresponds to mixed exogenous and endogenous feeding. At that time, the yolk platelets were gradually consumed until completely exhausted at 9 DPH. At the onset of Stage 3, the DG structure was completely tubular, exhibiting digestive cell microvilli and other cellular features typical to octupus DGs. During exogenous feeding (12 DPH and onward), acidophilic secretory lysosomes, heterolysosomes and some heterophagosomes appeared on DG cells. O. maya has long digestive cycles in which the extracellular and intracellular digestion can take up to 8 h. Although the ecological implications of this information for aquaculture will still have to be proven, results demonstrated that O. maya is an energetically efficient species and thus suitable for rearing in captivity.

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“…When HgCI2 or p-chloromercuribenzoate was used, dithiothreitol was omitted. For electrophoretic studies, addition of [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] pM leupeptin to the samples did not interfere with the activity after electrophoresis. When the effect of leupeptin on the acid activation process was studied enzymatically, samples were preincubated for 10 min at pH 3.5 or 3.75 with 0.5 pM inhibitor.…”

Section: Acid Pretreatment Of the Samplesmentioning

confidence: 99%

“…The studies published to date have focused either on the modifications the yolk undergoes, both ultrastructurally [2-61 and biochemically [2,5,, or on the identification of putative enzymes such as specific proteinases [lo-121. However, these reports are primarily descriptive and almost no evidence about the underlying mechanisms was presented.…”

Section: Fagottomentioning

confidence: 99%

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Yolk degradation in tick eggs: II. Evidence that cathepsin L‐like proteinase is stored as a latent, acid‐activable proenzyme

Fagotto

1990

Arch Insect Biochem Physiol

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Cathepsin L-like proteinase found in the eggs of the tick Ornithodoros moubata is latent during embryogenesis, but can be activated by acid treatment. In crude extracts as well as in partially purified fractions, activation requires reducing conditions and is inhibited by leupeptin, which indicates that it is mediated by a thiol proteinase, probably by the cathepsin L itself. Latency disappears in vivo at the time of the acute phase of yolk digestion, which takes place during late embryonic development and larval life. When egg cathepsin L is localized through its gelatinolytic activity on SDS-PAGE, the activated enzyme migrates as lower Mr bands than the latent form. Disappearance of the higher Mr bands corresponding to the latent form is directly related to appearance of the lower Mr bands characteristic of the active one; transition from one pattern to the other and enzymatic activation are in perfect agreement with regard to kinetics and sensitivity to inhibitors. The same pattern change occurs in vivo, parallel to latency removal and intense yolk degradation. These results strongly suggest that egg cathepsin L is stored in the yolk as a proenzyme which is activated by partial proteolysis at low pH.

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Degradation of yolk proteins in sea urchin eggs and embryos

Cited by 60 publications

References 20 publications

Gene expression profiling during the embryo‐to‐larva transition in the giant red sea urchin Mesocentrotus franciscanus

Gene expression profiling during the embryo‐to‐larva transition in the giant red sea urchin Mesocentrotus franciscanus

Cytological ontogeny of the digestive gland in post-hatching Octopus maya, and cytological background of digestion in juveniles

Yolk degradation in tick eggs: II. Evidence that cathepsin L‐like proteinase is stored as a latent, acid‐activable proenzyme

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