Gamete production for both males and females can be energetically expensive such that selection should maximize fertilization opportunities while minimizing fertilization costs. In laboratory studies of Drosophila reproduction, however, the failure of eggs to yield adult progeny can be quite high, suggesting that female control over gamete utilization is surprisingly inefficient. We examined ga...

During fertilization in eukaryotes, gametes of the opposite sex undergo a complex series of interactions that culminate in cell fusion. A new study on gamete interaction in plants has identified the first protein in multicellular organisms shown by gene disruption to be essential for gamete membrane adhesion.

Unreduced (2n) gametes have played a pivotal role in polyploid plant evolution and are useful for sexual polyploid breeding in various species, particularly for developing new seedless citrus varieties. The underlying mechanisms of 2n gamete formation were recently revealed for Citrus reticulata but remain poorly understood for other citrus species, including lemon (C. limon [L.] Burm. f.). Her...

BACKGROUND Assisted reproductive technology (ART) legislation in Sweden has undergone a gradual transformation from being fairly restrictive when first introduced to becoming more permissive in recent years. Regarding gamete donation, Sweden became the first country to pass legislation about disclosure by establishing a child's right to find out the identity of the gamete donor once the child h...

Gamete production and fertilization influence zygote production. While gamete production is correlated positively with body size, individual fertilization success may be a function of population density. Usually it is assumed that when high population density leads to reduced body size and gamete production, per capita zygote production is diminished. This field study of the sea urchin Diadema ...

BACKGROUND Although gamete receipt or donation has become an integral part of infertility management, previous research in the field of social attitudes and intention to use medical technologies is limited. The aim of this paper was to investigate people's intentions to receive or donate sperm, oocyte or uterus (surrogacy) and to identify possible motivational patterns explaining this intention...

1. Use of family members as donors or surrogates is generally ethically acceptable. 2. Brothers may donate sperm to brothers and sisters may donate eggs to sisters. 3. Intergenerational gamete donation and surrogacy are especially challenging. 4. Consanguineous gamete donations from first-degree relatives are unacceptable. 5. Counseling is encouraged for all parties including partners of donors...

1. Abstract 2. Introduction 2.1. Definition: purification versus complementation 2.2. Mutations 3. Some computer models 3.1. Emerging complementarity 3.2. Gamete recognition 3.3. Role of mutational pressure on the emerging of complementarity 3.4. The role of inbreeding 4. Consequences 4.1. Sympatric speciation 4.2. Distribution of recombination events 4.3. Effect of gamete recognition 5. Discus...

Anisogamy is the occurrence within a population of two gamete types of different size, a very common condition both in plants and in animals. This paper shows conditions that anisogamy without disassortative fusion (pseudoanisogamety) should be favoured by individual natural selection; the results obtained analytically below are in basic agreement with those obtained through the use of numerica...