Judul: Optimization of Electroporation with Green Fluorescent Protein Gene for Testicular Cell Transplant in Nile Tilapia
Abstrak: Transplantation technology can be applied to generate surrogate fish broodstock. Germinal cells as donor used in transplantation are labeled to distinguish with endogenous cells. Donor cells are generally derived from transgenic fish carrying a marker or cells labeled by PKH-26. This study was performed to obtain an alternative method of labeling cells by using electroporation. The method in this study includes the preparation of the recipient, the donor cell preparation and cell transplantation. Recipient was obtained by mating tilapia males and females with a ratio of 1:1. Testicular cells were taken from 4-month-old Nile tilapia. Electroporation was performed with testicular cell density of 104 cells.μL-1, pJfKer-GFP concentration of 50 ng.μL-1, and a pulse length of 20 ms at 0, 100, 200, and 300 volts. In amount of 5x103 cells at 0.5 μL electroporated testicular cells were then injected into the intraperitoneal cavity of 3-day-old Nile tilapia larva. The parameters measured were cell survival, the percentage of GFP fluorescent cells, and cell colonization in recipient fish. The results showed that survival of the electroporated cells with 100 and 200 volts was similar (p>0.05), and higher than that of 300 volt treatment (p<0.05). It shows that the voltage is very influential on cell survival. The increase in voltage will result in the increasing mortality in the cell. Number of fluorescent cells was not significantly different among treatments. While the percentage of fluorescent cells did not differ on the treatment of 100, 200, and 300 volts (p> 0.05) except for the control. In the control treatment luminescence GFP was not visible, it is proved that the GFP gene was not able to pass through the cell membrane in the absence of an electric voltage. Percentage colonization of transplanted cells in the fish after 50 days of rearing gave the highest value at 200 volts (66.67%). As conclusion, electroporation within 100-200 volt was a suitable tool to label testicular cells for transplantation.
Keyword: electroporation, GFP, label, Nile tilapia, transplantation

Judul: Xenotransplantation of giant gourami testicular germ cells into larvae of nile tilapia
Abstrak: We were attempting to develop testicular germ cell (TGC) transplantation as a tool to produce surrogate broodstock of commercially valuable fish and long generation time species. Giant gourami testis had been used as a model for donor and Nile tilapia larvae as recipient. The research was conducted to study the competency of giant gourami TGC as donor and Nile tilapia larvae as recipient for xenotransplantation of giant gouramy TGC into larvae of Nile tilapia. We developed TGC xenotransplantation system by some steps as follow : 1) The characterization of spermatogonia to identify optimal donor of giant gourami based on body weight using histological approach, 2) The determination of dissociation method for giant gourami testicular tissue by comparing two different composition of dissociation medium with 5 hours incubation time, 3) Optimizing the timing of intraperitoneal TGC transplantation into peritoneal cavity of 1, 3, 5 and 7 days post hatching (dph) recipient by investigating the colonization efficiency of donor cell labelled PKH 26 fluorescent membrane dye under fluorescent microscope and of molecular technique using growth hormone of giant gourami specific primer, 4 ) Analyzing the proliferation of spermatogonia colonized in recipient gonad using molecular approach, and 5) The evaluation of TGC isolated from testis of giant gourami which preserved at 4 oC using NaCl 0.7% for 6, 12, 24 and 48 hours and then transplanted into peritoneal cavity of recipient. The result showed that the donor with abundant spermatogonia stem cell and A type spermatogonia (cell diameter = 14.43–20.53 μm) were found in giant gourami with body weight ranged from 500–1000 g. The dissociation method produced high number of spermatogonia with high viability was one used medium PBS containing trypsin, DNase, CaCl2, HEPES, FBS and incubated for 3 hours. The highest colonization efficiency was observed at 3 dph recipient (61.1±34.71%) suggesting that 3 dph Nile tilapia larvae was the optimum recipient for transplantation. Intraperitoneally transplanted xenogenic spermatogonia efficiently colonized the ovary as well with sex ratio male out of female was 1:1, and possibly proliferated indicated by cell cluster forming and the increase of DNA concentration of donor in recipient testis during time interval 1 month to 2 or 3 month pt. The successful colonization of spermatogonia isolated from preserved testis were also observed with colonization efficiency not differed significantly as from non preserved testis. In conclusion : the testis of giant gouramy was composed of cells that had competency as donor for xenotransplantation using Nile tilapia larvae as recipient.
Keyword: Sel Testikular, Osphronemus goramy, Ikan Gurami, ikan nila, kolonisasi, proliferasi, preservasi

Judul: Analisis keamanan konstruksi fungsi hash berbasis sandi blok kunci simetrik (Kajian Teoritik)
Abstrak: Hash function is used to secure the integrity and authenticity of a massege, so that the message is save. The message which will be secured, will be attached to hash/message digest/digital signature value fro, the message. A secure hash function is the one which has pre-image resistance, 2nd pre-image resistance and collision resistance. Hash function has been classified into hash keyed function (Message Authentication Codes/MAC) and unkeyed (Modification Detection Codes/MDC)
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