Kinetic interference upon embryo development

Abstract

Biomphalaria glabrata (molúsco, gastrópodo), em diferentes estágios de desenvolvimento foi tratado com D 2O a 1% e 0,1 v/v em H 2O (~5 vezes a abundância nat u ral). Além de uma alta mortalidade em relação ao controle, observa-se uma velocidade de desenvolvimento extremamente baixa. Surpreendentemente, este an i mal pode ser mantido por ~1/3 da sua vida em dimensões reduzidas. O re torno às condições normais leva a uma retomada do desenvolvimento atingindo o estado de adulto após um intervalo de tempo muito maior do que o observado no controle. O real papel dos isótopos na natureza é questionado.Biomphalaria glabrata (mol lusc, gas tro pod), in dif fer ent de vel op ment stages were treated with D 2O at 1% and 0.1 v/v in H 2O (~5 times nat u ral abun dance). Be sides a high mor tal ity rate in re la tion to the con trols an amaz ing slow rate of de vel op ment was ob served. Sur pris ingl y, this an i mal may be kept for ~1/3 of its life in re duced di men sions. Re covering is how ever pos si ble. Upon re turn to nor mal con di tions they re sume de vel op ment reach ing adult stage in a much lo nger pe riod of time as com pared to the con trols. The ac tual role of iso topes in na ture is dis cussed Key words: Biomphalaria glabrata, deu te rium , en vi ron ment, iso tope, tox i col ogy In tro duc tionIso tope sub sti tu tion has been a quite com mon technique to in ves ti gate chem i cal re ac tions. More re cently [1][2][3][4] how ever, this same tech nique has shown a spe cial in ter est for stud ies con cern ing ac tiv ity of drugs 4 , com plex mech anisms such as taste of liv ing be ings, growth and trans forming ac tiv i ties of mi cro or gan isms, such as Strep to coc cus pneumoniae , cell sur vival 3 and tem per a ture shift, ef fect over some dis ease such us Fanconi's ane mia, and its ef fect upon hu man car ci noma.As it is well known, iso tope ef fect upon a chem i cal reac tion 9 is quite un pre dict able spe cially when we con sider chem i cal re ac tions among high mo lec u lar weight compounds are con sid ered. Ob vi ously, more un pre dict able effects can be ex pected when deal ing with liv ing or gan isms where the mod i fied mol e cules take part of an enor mous num ber of re ac tions in con cert. In this pa per we deal with the ef fect of iso tope sub sti tu tion upon the pro cess of growth of an an i mal from its em bryo phase. For the purpose we have cho sen as our sub ject Biomphalaria glabrata (mol lusc, gas tro pod) in dif fer ent de vel op men tal stages (Phase I, close to 130 blastomers; II , Vel iger , 5 days af ter first cleav age; III , al ready formed em bryo , ready to hatch out, and IV , al ready ecloded, two days old). Ma te rials and MethodBiomphalaria glabrata , from the State of Minas Gerais, Brazil was used in the pres ent re search. Adults were raised in lab o ra tory for ten years. Biomphalaria glabrata is a si mul ta neous her maph ro dite and re pro duce ei ther by selfing or cross-fertilization. In the pres ent research em bryos and adults were used. The adults were r...