Purine-Induced Block to Mouse Embryo Cleavage is Reversed by Compounds that Elevate Cyclic Adenosine Monophosphate

BIOLOGY OF REPRODUCTION 47, Purine-Induced 1105-1112 Block (1992) to Mouse Elevate R Departments Laboratoiy for Embryo Cyclic FISSORE,3 Human Adenosine S. of Obstetrics, Cleavage Reproduction Harvard by Compounds That Monophosphate1 and O’KEEFE,4’6 Gynecology Is Reversed and A.A. KIESSLING2’3’5 Reproductive and Reproductive Medical School, Biology3 and Biology,5 and Dana Boston, Massachusetts Pathology4 Farber Cancer Institute6 The or third second To begin to the of the stage reverse the cAMP. Our SV4O promoter proteins block cell cycle not of the blocked; not prevent several studied of RNAs transfer 1) that the embryos 3) overall reverse early the embryonic gene of the cell interphase 6) and expression cycle that work in this concentrations of several tro. The reasons not been phenomenon mined strains can by the [1, 2]. The h after for discovered, are profound cleavage cultured purine not by the exposed [2].Zygotes in purine-containing development conditions tive process [1, 2]. The precise window is not known, but embryos sensitive until following approximately have as 10 for 24 transfer to purine-free lines of the purine-sensiconceived in vivo 28-30 h after nor or adenosine incorporation of thymidine [2], in keeping occurs due with late the in the to the into nuclear possibility that S phase or cell cycle. These characteristics inhibit a critical cell process of cumulation and cAMP metabolism during the suggest that does may not sent blocked sensitive G2 strains [2]. The is not DNA the or of the that some purines not result in the ac- depend upon However, initiate cell August Received November ‘Supported preliminary Society in part report meeting, of 1992. some Medicine, National Institutes of this DC, work Oct., of Health was Grants presented 21988 at the and American 21980. A Fertility and current address: Centre Street, A.A. Boston, Kiessling, Faulkner Centre for control mechanism the block that is involved Re- salts MA 02130. 1105 arise from could be the the two-cell in the “two-cell into of some subop- two-cell stage to cell that division to in vitro supplemented overcome Earle’s that in blocking stores rather Moreover, a from embryos in the that non-blocking G2 are ab- strains. of messages embryonic maternal involved. is also embryos has been ifthe transferred maternal early block of cytoplasm that two-cell blocking genome expression that it can be ranging from medium as the of concentrations is a response diaminetetraacetic the embryonic to a characteristic when explanted in G2 that of transi- early known essential notion are fact of cell functions could lead to critical trait [5, 6]. Transfer factors or factors (EBSS) 1990. 1153 late indicate could servations conditions 25, 1991. by Washington, 2Correspondence productive ii, The period to blastocysts, but if explanted earat the two- to four-cell stage. Several the fact embryonic supports metabolic onic Accepted factors the a critical time period refers that, at sub-effective proteins, Thus, the phenomenon derived contain or Such process phase inhibit cytoplasm is derived from non-blocking phase of the cell cycle [7]. This suggests of hypoxan- monophosphate do non-blocking to blocking strains of mouse reported to reverse the block, particularly fertilization, arrest is not the result of the inhibition of cAMP-dependent thine to guanosine of evidence block. during about conditions maternally and are no longer sensitive by 34 h [1].The developmental phosphodiesterase, culture cytoplasm the intermediates. information undergo development lier become arrested to embryonic in cAMP. 13, 4]. The term of mouse embryos timal to elevate Z linked of lac of early but occurs described that compounds reverse purine arrest attempted of additional did events, to other new block” strains or early two- medium cAMP by elevations compensated extensively sperm as early microinjection including we 2) the expression processes. A similar developmental of the is deter- fertilizing affected h resume are sensitivity with phosphorylation important in vi- characteristics sensitivity of embryos is not be most In addition, tion from maternal to embryonic indicates that understanding the cleav- developing several Purine of mother, fertilization cell embryos embryos although now known. strain first the or 5) elevate purine-induced that and or third block the second of mouse affected; that of hypoxanthme. embryos, but the appearance depressed conversion laboratory [1, 2] demonstrated of hypoxanthine, adenosine, inosine, but not guanosine, age not was presence in blocked co-culture and in interphase; was compounds INTRODUCTiON Previous micromolar blocked in the metabolism phosphorylation. cells, synthesis of proteins block; protein dividing were protein of cell aspects and from is blocked of females strains several translation, phosphorylation overall during from we of transcription, cytoplasm, did not occurring levels following: 4) embryos do embryos of the block, but not blocked; depressed, apparently process the and indicate was non-blocking purines mechanism by transfer results was from cell of mouse cleavage the determine gene products. embryos successfully seem than evidence stresses early that stems by improved balanced salts to [4,8] embrythe two- from ob- culture solution with lactate, pyruvate, and ethyleneacid (EDTA) with protein, amino [9] to glucose-free acids, and balanced EDTA [10, 11]. ABSTRACT 1106 FISSORE The relationship two-cell block stages of these cycle between is unknown, sensitivities is a particularly cidating to fully mal the purine-induced but the similar emphasize that delicate the crucial understand time cell pathways embryonic development in vitro embryos. depend on recognition and protein discover phosphorylation; conditions to reverse of investigation, two to transfer cytoplasm blocking pounds measured the transcription, and the the block. utilized: embryo in culture, periments in the viously described protein[9]. and Zygotes Fl we carried out amino acid-free AND recovered of two inbred Labs., Bar Harbor, strain; Charles duced River, Wilmington, with i.p. injections Jackson St. Louis, (Sigma fertile ulation MO), Chemical BDF (5-50 plug the Collection Co., Grand V; Sigma Island, Chemical were Survival and (Swiss Webster, (random-bred MA). Superovulation of 5 IU of eCG (Sigma pacted and contained contained a blastocoele Culture following and morning (16-18 At all times, the (...truncated)