The life cycle of eukaryotic, sexual species is divided into haploid and diploid phases. In multicellular animals and seed plants, the diploid phase is dominant, and the haploid phase is reduced to one, or a very few cells, which are dependent on the diploid form. In other eukaryotic species, however, the haploid phase may dominate or the phases may be equally developed. Even though an alternat...

Research Question: Is maternal age only a gross predictor of chromosome abnormalities in human embryos? Design: Here, we evaluated the less-studied variation abnormality rates embryos patients within same group. Patients undergoing IVF and PGD for chromosomal ~127 different clinics were included. PGT-A analysis was performed by single reference laboratory using array CGH or NGS. To get an estim...

The assessment of oocytes showing only one pronucleus during assisted reproduction is associated with uncertainty. A compilation of data on the genetic constitution of different developmental stages shows that affected oocytes are able to develop into haploid, diploid, and mosaic embryos with more or less complex chromosomal compositions. In the majority of cases (~80%), haploidy appears to be ...

Identifying the physical basis of heterosis (or "hybrid vigor") has remained elusive despite over a hundred years of research on the subject. The three main theories of heterosis are dominance theory, overdominance theory, and epistasis theory. Kacser and Burns (1981) identified the molecular basis of dominance, which has greatly enhanced our understanding of its importance to heterosis. This p...

Male factors leading to infertility account for at least half of all cases of infertility worldwide. The purpose of this review is to highlight the importance of sperm DNA integrity. A systematic literature search was performed up to January 2015 in order to determine the impact of sperm DNA integrity and of the techniques used to determine it. Only articles presenting sperm aneuploidy together...

OBJECTIVE This study aims to increase the knowledge about monopronucleated ICSI-derived blastocysts, analyzing trophectoderm biopsies by aCGH and FISH to evaluate their chromosome constitution. METHODS Fifteen monopronucleated ICSI-derived blastocysts were studied. Double trophectoderm biopsy was performed and analyzed by FISH and aCGH. The blastocysts were classified according to chromosome ...

The evolution of haploid and diploid phases of the life cycle is investigated theoretically, using a model where the relative length of haploid and diploid phases is under genetic control. The model assumes that selection occurs in both phases and that fitness in each phase is a function of the time spent in that phase. The equilibrium and stability conditions that allow for all-haploid, all-di...

Mammalian somatic cells are usually diploid. Occasional rare human tumors have been shown to have a hypodiploid karyotype. We have isolated a near-haploid subclone (P1-55) from a heterogeneous human leukemia cell line, KBM-7. These near-haploid cells have approximately half the human diploid DNA content and have a haploid karyotype except for a disomy of chromosome 8 (25, XY, +8, Ph(+)). This c...

Sexual reproduction proceeds by fertilization; formation of new individuals by the union of haploid gametes. Recent reports in Cell and in Developmental Cell may provide new insights as to how this process begins and is regulated.