Fertilization occurs when the materials from two gametes come together to form an embryo. The female gamete is often referred to as the egg or female germ cell whereas the male gamete is often referred to as sperm or the male germ cells (Burfoot, 1999). Developing female germ cells are generally large and contain nutrient reserves including what is referred to as the egg yolk and typically are immobile (Burfoot, 1999).
Male germ cells are highly mobile if normal and generally contain little nutritional recourses; most are very tiny and contain substances called centrosomes (Burfoot, 1999). Male and female germ cells both contain a set of chromosomes and hence are referred to as haploid. After fertilization occurs a zygote results containing two sets of chromosomes now called the diploid.
Successful fertilization can only occur when the male and female germ cells both are at proper stages of fertilization. Mature male cells are thus capable of penetrating female germ cells or the egg. After fertilization the female germ cell supplies cytoplasm and nutrients to nourish the embryo while the male sperm or germ cells provides more functional centrosome to encourage mitosis or cell division.
Prior to fertilization germ cells reside in the seminiferous tubules at varying levels of maturation and exist alongside sertoli cells or non-dividing cells whose sole purpose is support (IVF, 2005). These cells are linked by tight junctions to male germ cells resting along the "basement membrane of the seminiferous tubules" (IVF, 2005). Male germ cells are isolated prior to spermatogenesis to maintain...