Ovorubin (PcOvo or PcPV1) is the most abundant perivitellin (>60 % total protein) of the perivitelline fluid from Pomacea canaliculata snail eggs. This glyco-lipo-caroteno protein complex is a approx. 300 kDa multimer of a combination of multiple copies of six different ~30 kDa subunits.[1]
Together with the other perivitellins from Pomacea canaliculata eggs, ovorubin serves a nutrient source for developing embryos, notably to the intermediate and late stages.[2] Moreover, after hatching, the protein is still detected in the lumen of the digestive gland ready to be endocytosed, therefore, acting as a nutrient source for the newly hatched snail.[2]
Ovorubin contains carbohydrates and carotenoid pigments as main prosthetic groups, [3] which are related to many physiological roles on Pomacea aerial egg-laying strategy. Given that carbohydrates tend to retain water, the high glycosylation of ovorubin (~17 % w/w) was proposed as an embryo defense against water loss.[3] The carotenoid pigments stabilized by ovorubin also provide the eggs of antioxidant and photoprotective capacities, crucial roles to cope with the harsh conditions of the aerial environment.[2][4][5][6][7][excessive citations] The presence of carotenoid pigments is also responsible for the brightly reddish coloration of Ovorubin, and therefore snail eggs, which was related to a warning coloration (aposematism) advertising predators about the presence of deterrents.[8][9] In fact, field evidence of egg unpalatability is provided by the fact that most animals foraging in habitats where the apple snails live ignore these eggs.[10]
Like most other studied perivitellins from Pomacea snails, ovorubin is highly stable in a wide range of pH values and withstands gastrointestinal digestion, characteristics associated with an antinutritive defense system that deters predation by lowering the nutritional value of the eggs.[11][12]
^ abcHeras H, Garin CF, Pollero RJ (1998). "Biochemical composition and energy sources during embryo development and in early juveniles of the snail Pomacea canaliculata (Mollusca: Gastropoda)". Journal of Experimental Zoology. 280 (6): 375–383. doi:10.1002/(SICI)1097-010X(19980415)280:6<375::AID-JEZ1>3.0.CO;2-K. ISSN1097-010X.
^ abDreon MS, Heras H, Pollero RJ (July 2004). "Characterization of the major egg glycolipoproteins from the perivitellin fluid of the apple snail Pomacea canaliculata". Molecular Reproduction and Development. 68 (3): 359–64. doi:10.1002/mrd.20078. PMID15112330. S2CID22032382.
^Dreon MS, Heras H, Pollero RJ (January 2003). "Metabolism of ovorubin, the major egg lipoprotein from the apple snail". Molecular and Cellular Biochemistry. 243 (1–2): 9–14. doi:10.1023/A:1021616610241. PMID12619883. S2CID6345962.
^Dreon MS, Schinella G, Heras H, Pollero RJ (February 2004). "Antioxidant defense system in the apple snail eggs, the role of ovorubin". Archives of Biochemistry and Biophysics. 422 (1): 1–8. doi:10.1016/j.abb.2003.11.018. PMID14725852.
^Dreon MS, Ceolín M, Heras H (April 2007). "Astaxanthin binding and structural stability of the apple snail carotenoprotein ovorubin". Archives of Biochemistry and Biophysics. 460 (1): 107–12. doi:10.1016/j.abb.2006.12.033. PMID17324373.
^Snyder NF, Snyder HA (1971-01-01). "Defenses of the Florida Apple Snail Pomacea Paludosa". Behaviour. 40 (3–4): 175–214. doi:10.1163/156853971X00384. ISSN0005-7959.