Aquarium Saltwater Marine Protein Skimmer for tanks over 1,000 gallons
100 gallon custom reef , refugium, protein skimmer, t5 Halide LED, Cabinet
Aquarium Engineering 12 inch protein skimmer . commerical protein skimmer
ATB Deluxe 18" Internal Aquarium Saltwater Marine Protein Skimmer, 1500+ Gallons
Super Reef Octopus 7000 External Recirculating Protein Skimmer
AquaMaxx Cone 7 In-Sump Protein Skimmer
Super Reef Octopus XP-8000 External Protein Skimmer by CoralVue
Bubble Magus Cone Skimmer BM-NAC7 2011 Model
Bubble Magus Cone Protein Skimmer Curve 5 2012-2013 Aquarium Reef Marine
Super Reef Octopus XP-8000 Internal Protein Skimmer by CoralVue
Cat Cloning and Other Reproductive Technologies
This article looks at several areas of what is known as 'reproduction technology' and how it could affect cat breeders and cat owners. These pros and cons will also apply to other pets. Reproduction technology includes cloning, artificial insemination, egg donation, embryo transfer and IVF. I have basic knowledge and understanding, but do not claim to be an expert in these fields. I have written this so that an owner or breeder with little or no prior knowledge can understand it. I have included general interest comments about some of the wider issues of cloning in species other than cats.
- Cloning is the creation of a genetically identical cat from a cell taken from a host (the genetic parent) and grown into a kitten inside a surrogate mother.
- Artificial insemination using stored sperm is the gathering of sperm from an unneutered cat and the impregnation of a female cat using that sperm.
- Egg donation is the harvesting of a freshly ovulated, unfertilized egg from one female; the egg is fertilized in vitro (i.e. "test tube fertilization") and implanted into a surrogate who cannot ovulate
- Embryo transfer is the implantation of an embryo or fertilized egg (one which has already begun to divide ad grow) into a surrogate mother. The embryo (or the egg and the sperm used to make it) might have been kept stored in liquid nitrogen for a period of time before being implanted into the surrogate mother.
- IVF is in vitro fertilization, often known as 'test tube fertilization'.
- Ova means 'egg cells'.
A Few Basics
The following is greatly simplified and is based on information in Matt Ridley's excellent book "Genome" and has been adapted for cat owners. However, you can skip this section if you prefer. It is provided to give an understanding of cell division and why there are still problems with cloning technology.
The cells in a cat's body continually divide and replace themselves. Cells multiply during growth to make more tissue and skeleton as the kitten grows and matures. When the cat is full grown, cells continue to reproduce themselves. Cells wear out and die and are replaced by newer ones copied from the old cell. As the cat gets older, the cells are less efficient at making exact copies of themselves and mistakes creep in.
It's like monks copying books by hand - sometimes a spelling error creeps in; the monk who copies the new manuscript also copies the spelling error and maybe adds another error. As the mistakes accumulate, the cat (the host body that the cells live in) shows signs of ageing.
How does the cell know how many time it has divided? The genes (lengths of DNA) are stored as strings called chromosomes in the cell nucleus. DNA is like an alphabet; the gene is like a word and the chromosome is like a sentence. At the ends of each chromosomes is a telomere - these are like strings of full stops. In young kittens, the telomeres are relatively long and there are lots of full stops in each telomere. Each time the cell divides, the telomere gets shorter as a full stop is lost off of the end. This is part of the ageing process and seems to be why animals grow old. The telomeres are also like a clock, telling the chromosome in the cell how old the cat is.
(Continued on next page)