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Teknologi DNA rekombinan

Teknologi DNA rekombinan telah mungkinkan bagi kita untuk: mengisolasi DNA dari berbagai organisme, menggabungkan DNA yang berasal dari organisme yang berbeda sehingga terbentuk DNA rekombinan, memasukkan DNA rekombinan ke dalam sel organisme prokariot maupun eukariot hingga DNA rekombinan dapat berepilkasi dan bahkan dapat diekspresikan. Jadi, Teknologi DNA Rekombinan merupakan kumpulan teknik atau metoda yang digunakan untuk mengkombinasikan gen-gen di dalam tabung reaksi. Teknik-teknik tersebut meliputi:

- Teknik untuk mengisolasi DNA.

- Teknik untuk memotong DNA.

- Teknik untuk menggabung atau menyambung DNA.

- Teknik untuk memasukkan DNA ke dalam sel hidup.

perangkat yang digunakan dalam teknologi DNA rekombinan adalah perangkat-perangkat yang ada pada bakteri. Perangkat tersebut antara lain adalah: enzim restriksi, enzim DNA ligase, plasmid, transposon, pustaka genom, enzim transkripsi balik, pelacak DNA/RNA.

Enzim restriksi digunakan untuk memotong DNA

Enzim DNA ligase digunakan untuk menyambung DNA

Plasmid digunakan sebagai vektor untuk mengklonkan gen atau mengklonkan fragmen DNA atau mengubah sifat bakteri.

Transposon digunakan sebagai alat untuk melakukan mutagenesis dan untuk menyisipkan penanda.

Pustaka Genom digunakan untuk menyimpan gen atau fragmen DNA yang telah diklonkan.

Enzim traskripsi balik digunakan untuk membuat DNA berdasarkan RNA.

Pelacak DNA / RNA digunakan untuk mendeteksi gen atau fragmen DNA yang diinginkan atau untuk mendeteksi klon yang benar.

VAGINAL SMEAR

Cytologic Changes Through the Canine Estrous Cycle

Stages of the canine estrous cycle can be defined by sexual behavior, physical signs (vulvar swelling, vaginal bleeding) or by vaginal cytology. The period of receptivity to a male varies considerably among bitches; some bitches are receptive well before and after the period of potential fertility. Similarly, signs such as "proestrus bleeding" are often unreliable indicators; some bitches bleed very little and other show bleeding through estrus and into diestrus.

Since cytologic changes reflect the underlying endocrine events of the cycle, they are almost always a better predictor of the "fertile time" and gestation length than are behavioral or physical signs.

Cytologic changes through the canine estrous cycle reflect changes in blood concentrations of estrogen. As depicted below, and described in more detail in the section on Canine Reproduction, estrogen levels rise prior to and during proestrus and fall in conjunction with the preovulatory surge of luteinizing hormone. Rising levels of estrogen induce the "cornification" that is characteristic of smears examined during estrus. Ovulation occurs two days after the LH surge.

The sections below describe the cytologic picture typical of different stages of the canine estrous cycle. Examination of a single smear can sometimes provide useful information, but can also be quite misleading. For example, it is often difficult to differentiate proestrus and diestrus from an isolated smear. It is therefore highly recommended that multiple smears be evaluated.



berikut alamat jurnal yang dapat didownload langsung
jurnal ini berisi informasi tentang penggunaan metode vaginal smear

http://jeb.biologists.org/cgi/reprint/28/4/585.pdf
http://www.springerlink.com/content/l22p0832k12k040m/fulltext.pdf?page=1
http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=1520238&blobtype=pdf
http://www.scielo.br/pdf/spmj/v122n2/a08v1222.pdf
http://www.royal-canin.co.kr/admin/upload/vaginal%20smears%20in%20bitches.pdf
http://caonline.amcancersoc.org/cgi/reprint/20/3/168.pdf
http://la.rsmjournals.com/cgi/reprint/36/1/51.pdf
http://jn.nutrition.org/cgi/reprint/112/8/1481.pdf
http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=1843599&blobtype=pdf
http://www.ajronline.org/cgi/reprint/102/1/170.pdf
http://journals.tubitak.gov.tr/veterinary/issues/vet-06-30-5/vet-30-5-6-0509-42.pdf
http://196.33.159.102/1970%20VOL%20XLVI%20Jul-Dec/Articles/06%20December/1.9%20USE%20OF%20VAGINAL%20SMEAR%20IN%20ASSESSMENT%20OF%20OESTROGENIC%20STATUS%20OF%20OOPHORECTOMIZED%20FEMALES,%20Wulf%20H.%20.pdf

Human cloning

Human cloning is the creation of a genetically identical copy of a human being, human cell, or human tissue. The term is generally used to refer to artificial human cloning, although human clones in the form of identical twins are commonplace, with their cloning part of the natural process of reproduction.

Although genes influence behavior and cognition, "genetically identical" does not mean altogether identical; identical twins, despite being natural human clones with nearly identical DNA, are separate people, with separate experiences and personalities. The relationship between an "original" and a clone is rather like that between identical triplets raised apart; they share nearly all of the same DNA, but little of the same environment. A lively scientific debate on this topic occurred in the journal Nature in 1997.^[1] Ultimately, the question of how similar an original and a clone would be boils down to how much of personality is determined by genetics, an area still under active scientific investigation. (See nature versus nurture and cloning.)

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