Hakan Sagirkaya

Uludag University · Faculty of Veterinary Medicine

Pet hayvanlarında biyoteknolojik çalışmalar son yıllarda hız kazanmaya başlamıştır. Köpeklerde başarısız yardımcı üreme teknikleriyle ilgili oluşan sorular, muhtemelen köpek türlerinin reproduktif fizyolojisine ait yetersiz bilgiden kaynaklanmaktadır. Fakat diğer taraftan pet biyolojisindeki uygulamalar, insan hastalıkları için model oluşturmaktadı...

Saha şartlarında sperma almak ve tohumlama yapmak her zaman aynı koşullarda ve temiz şartlarda yapılamamaktadır. Bu çalışmada saha şartlarında üç farklı dozda intraservikal yolla suni tohumlama uygulaması sonucunda gebelik oranlarının araştırılması amaçlandı. Araştırmada Doğu Friz ırkı 60 adet koyun 3 gruba ayrıldı (n=20) ve 3 adet koç kullanıldı....

Bu çalışmada embriyo transferi sırasında taşıyıcı Holstein ırkı ineklerin kan progesteron seviyelerinin gebelik oranları üzerine etkisinin belirlenmesi amaçlandı. Bu amaçla, 5 üstün genetik özelliklere sahip donör inek ve 36 taşıyıcı inek hayvan materyali olarak kullanıldı. Donörlerde süperovulasyon östrusun 9. gününde başlayan 12 saat ara ve 4 gün...

Bu çalışma, gökkuşağı alabalığı seminal plazmasının (RTSP) bal arısı drone spermatozoonu üzerindeki etkilerini eritme sonrası araştırmayı amaçladı. Cinsel açıdan olgun erkek arılardan sperm örnekleri toplandı ve havuzlandı. Daha sonra havuzlanmış semen, farklı konsantrasyonlarda RTSP (% 2.5 /% 5 /% 10) ile ve RTSP (kontrol) takviyeli sulandırıcılar...

In this study, it was aimed to determine the effect of destruction of lyophilized and frozen-thawed ram sperm plasma and acrosomal membrane on development of embryos produced by intracytoplasmic sperm injection (ICSI). Semen samples were divided into two groups for lyophilization (L) and freezing (F). For the removal of the plasma membrane, L and F...

The aim of this study was to evaluate the eff ects of autologous platelet-rich plasma (PRP) supplemented egg yolk based extender on ram semen after thawing. Semen samples were collected from nine Kıvırcık rams and each semen was divided into four equal aliquots and mixed with diff erent concentrations of PRP supported extenders [no PRP (control), 1...

The aim of study was to investigate the effect of corpus luteums (CL) size that detected before embryo transfer on conception in recipient Holstein cows. The recipient cows utilized had at least one birth and aged 3-8 years old. PGF2α was injected 2 times space 14 days apart to cows and 87 cows which show estrous symptoms were determined as recipie...

The objective of the current study was to evaluate the effect of autologous platelet-rich plasma (PRP) addition into soybean lecithin based extender on buck semen at post-thaw. Semen samples were collected from eight Saanen buck, and each semen sample was split into four equal aliquots and diluted with different concentrations of PRP supplemented e...

The study aimed to evaluate the eff ects of L-carnitine on honey bee (Apis mellifera) drone spermatozoon at post-thaw. Semen samples obtained from sexually mature drones were pooled. Then, pooled semen was diluted with diff erent concentrations of L-carnitine (2.5 mM/ 5 mM/ 10 mM) and without L-carnitine (control) supplemented extenders. Motility,...

This study was performed to compare the effects of embryo quality on pregnancy outcome in recipient cows and heifers. Embryos obtained from 83 Holstein donors were used in the study. In order to synchronize the recipients, 500 μg of cloprostenol were administered intramuscularly (im), twice, at an interval of 11 days. In all recipients, one embryo...

The aim of this study was to determine the effects of the administration time of misoprostol (11 h (Miso11) and 6 h (Miso6) before artificial insemination) on fertility rates in Kivircik ewes (control: n = 41, Miso11: n = 32 and Miso6: n = 33) during breeding season. Artificial insemination (AI) was performed 48 h after sponge removal using frozen-...

The aim of this study was to determine the effects of both the removal of seminal plasma (SP) and the pre-freezing addition of seminal plasma collected during the breeding or nonbreeding season on goat sperm survival after thawing. Semen samples were pooled. One aliquot of pooled semen was used as a control group. Four aliquots were then centrifuge...

Summary: The aim of the current study was to evaluate different antioxidant-supplemented extenders for post-thaw semen quality and incubation resilience of ram spermatozoa. Pooled semen samples were divided into four equal volumes and each volume were diluted with two-step dilution method in control and antoxidant supplemented groups (5mM methionin...

Preimplantation genetic diagnosis is the detection of inherited diseases and the sex of embryos before implantation in the practice of human medicine as well as in veterinary medicine. The introduction of experimental animal embryo biopsy techniques has been a milestone in the developmental process of preimplantation genetic diagnosis techniques. T...

The aim of the current study was to evaluate the effects of different concentrations of rainbow trout seminal plasma (RTSP) (0.1%, 1% and 10%) in extenders containing either egg yolk or lecithin for use in Awassi ram semen cryopreservation. Pooled sperm were diluted in a two-step dilution method to a final concentration of 1/5 (semen/extender) in e...

The aim of this study was to evaluate the effects of lyophilized egg yolk extender on ram semen cryopreservation. Ejaculates with a thick consistency, rapid wave motion (3-5 on a 0-5 scale) and >75% initial motility were pooled. Sperm were diluted to final concentration of 1/5 (semen/extender) in lyophilized egg yolk or fresh egg yolk extenders usi...

Anatolian grey cattle (endangered native Anatolian cattle) as 1 male (clone 1) and 4 females (clones 2-5) were produced from cells of 1 male and 1 female cattle by somatic cell nuclear transfer (SCNT) in a previous study. In this study, we examined the reproductive potential of these cloned animals, which are now 4 and 5 years old. The parameters e...

This study investigates the effect of freezing rates on the spermatological parameters of frozen and thawed Saanen goat semen. Equilibrated semen was frozen at 4 different freezing rates from +5 degrees C to -150 degrees C (G10: 10 degrees C/min, G12: 12 degrees C/min, G15: 15 degrees C/min, and G24: 24 degrees C/min) and stored in liquid nitrogen...

The aim of the present study was to evaluate the correlation between the routine semen analyses and sperm DNA integrity, as assesed by TUNEL in fresh semen of rams in Kivircik and Awassi breeds in breeding season. Semen was collected by electro-ejaculation five times every other day. For that purpose, 50 fresh ejaculates from 6 Kivircik and 4 Awass...

The aim of the current study was to evaluate the effect of egg yolk and different soybean lecithin concentrations on the efficiency of ram semen cryopreservation and to test the fertilizing ability of frozen-thawed ram semen. Ejaculates with a thick consistency, rapid wave motion (3-5), and >70% initial motility were pooled. Pooled semen were then...

The present study compared superovulation and embryo recovery rates applied repeatedly during breeding and nonbreeding seasons in the same 20 Kivircik sheep. Trials 1 and 3 were performed during the breeding season and the trial 2 was performed in the nonbreeding seaSon. We synchronized the sheep's estrus cycles and induced a superovulatory respons...

The effect of Chronogest-supplemented Ovsynch and Co-synch protocols on estrus synchronization, follicular development, and fertility after fixed-time insemination was investigated in goats during the breeding season. Co-synch (n = 24) and Ovsynch (n = 25) protocols were applied to nulliparous does with a body weight of more than 30 kg. The onset a...

In vitro development ratios, quality evaluation, in vivo implantation, and fetal development ratios were investigated following aspiration biopsy in 8-cell mouse embryos and trophectoderm biopsy in blastocyst developed from 8-cell stage embryos in vitro. Superovulated CB6F1 hybrid female mice (5-6 weeks) were sacrificed 68 to 72 hours after hCG adm...

Vitrification is becoming a preferred method for pre-implantation embryo cryopreservation. The objective of this study was to determine the differentially expressed genes of in vivo- and in vitro-produced bovine embryos after vitrification. In vitro- (IVF) and in vivo-derived (IVV) bovine blastocysts were identified as follows: in vitro-produced fr...

The aim of this study was to clone native Anatolian Grey cattle by using different donor cell types, such as fibroblast, cartilage and granulosa cells cryopreserved in a gene bank and oocytes aspirated from ovaries of Holstein cows as the recipient cytoplasm source. One male calf from fibroblast, three female calves from granulosa cells and one fem...

The aim of the present study was to investigate the suitability of the water test and hypo-osmotic swelling (HOS) test for analyzing honeybee semen. In particular, the relationships between these tests of the integrity of the sperm plasma membrane and tests of sperm motility and sperm viability were measured using SYBR-14/PI. To this end, semen wa...

The objective of the present study was to investigate the effect of different freezing rates on post-thaw sperm motility, acrosome defect, and sperm chromatin structure and apoptotic activity in ram semen. Collected semen was diluted at 1:5 (semen/extender) with Bioxel® (IMV technologies France) at 30° and then cooled to 5° within 1h. Cooled semen...

The objective of the present study was to investigate the effect of different freezing rates on post-thaw sperm motility, acrosome defect, and sperm chromatin structure and apoptotic activity in ram semen. Collected semen was diluted at 1:5 (semen/extender) with Bioxel® (IMV technologies France) at 30ºC and then cooled to 5ºC within 1h. Cooled seme...

Microarray technology is one of the most powerful tools for gene expression profiling in animal sciences. The objectives of this study were to determine the effect of vitrification on gene expression in in vitro- and in vivo-derived bovine embryos, and to identify differential mRNA expression patterns between embryos produced by in vivo v. in vitro...

This study investigates the effects of glycerol, 1,2 propanediol, sucrose, and trehalose on post-thaw motility, morphology, and genome integrity of Awassi ram semen. Ejaculates of thick consistency with rapid wave motion (>+++) and >70% initial motility were pooled. Sperm were diluted to a final concentration of 1/5 (semen/extender) in 0% cryoprote...

In vitro embryo culture is an important step of in vitro production of bovine embryos. The aim of this study was to compare the in vitro development of bovine embryos in G1.3/G2.3 sequential culture media and CR1aa culture medium. Oocytes were obtained from ovaries of slaughtered cows and matured in TCM-199 medium in humidified air containing 5% CO...

One of the application fields of nuclear transfer (NT) is to increase the population of endangered mammals. In the present study, cloning of native Anatolian Grey Cattle living semi-wildly especially in the Marmara Region was aimed. Bovine oocytes isolated from slaughterhouse ovaries were matured in TCM-199 supplemented with 10% fetal bovine serum...

Diverse groups of chemicals in culture media are needed for successful bovine oocyte maturation and embryo development during which dramatic cytoplasmic and nuclear reprogramming events take place. In vitro embryo production (IVP) procedures frequently include supplements such as serum and/or co-culture with various types of somatic cells. However,...

Germinal vesicle (GV) breakdown is fundamental for maturation of fully grown, developmentally competent, mammalian oocytes. Bidirectional communication between oocytes and surrounding cumulus cells (CC) is essential for maturation of a competent oocyte. However, neither the factors involved in this communication nor the mechanisms of their actions...

The influence of different extender osmolality levels and the presence of different cryoprotectants on the post- thawed semen's characteristics and post-thawed plasma membrane integrity of ram spermatozoa were studied. Ram semen was frozen with TRIS-egg yolk based extender according to two-step dilution procedures. The final concentrations of the c...

Global activation of the embryonic genome is the most critical event in early mammalian development. After fertilization, a rich supply of maternal proteins and RNAs support development whereas a number of zygotic and embryonic genes are expressed in a stage-specific manner leading to embryonic genome activation (EGA). However, the identities of em...

Expression of embryonic genes is altered in different culture conditions, which influence developmental potential both during preimplantation and fetal development. The objective of this study was to define the effects of culture conditions on: bovine embryonic development to blastocyst stage, blastocyst cell number, apoptosis and expression patter...

Dramatic reprogramming of gene expression occurs during embryonic genome activation (EGA), an essential event initiating as early as the 1-cell zygotic stage in the bovine and increasing gradually as embryonic development advances. It is this reprogramming of gene expression that sets the stage for later development. Expression of embryonic genes i...

Adequate regulatory proteins, growth factors, and hormones in in vitro embryo culture systems are important for improving the quality of embryos to a level similar to that in vivo conditions. The objective of this study was to define the effects of leptin, insulin-like growth factor-1 (IGF-1), and their combination on embryonic development, apoptos...

The aim of the study was to evaluate the effect of the addition of 20% bull seminal plasma to semen extenders on post-thaw sperm motility, morphology, and fertility. Two Merino rams at 3-5 years of age, 43 ewes, and one Holstein bull were used. Fourteen ejaculates were collected by the use of an artificial vagina, twice a day, at 60 min interval. S...

The objective of this study was to investigate the effect of low temperature thawing and post-thaw cold shock application on sperm motility, as well as acrosomal and plasma membrane integrities of cryopreserved bull semen. Frozen semen was thawed in a water bath at 5-7°C for 30, 60 or 90 s (low thawed groups), cold shocked (at 5-7°C for 30, 60 or 9...

The efficiency of medroxyprogesterone acetate (MAP) and fluorogestone acetate (FGA) sponges with or without PGF 2α (cloprostenol) for synchronizing estrous in non-lactating does was investigated during the natural breeding season. Does were treated for 11 days with 60 mg MAP ( n = 38) or 40 mg FGA ( n = 32) sponges. All does also received intramusc...

The cryopreservation of pronuclear-stage embryos has particular importance in transgenic technology and human assisted reproductive technology (ART). The objective of this study was to improve the efficiency of cryopreservation of pronuclear-stage mouse embryos. Two vitrification methods (solid surface vitrification (SSV) vs. vitrification in cryot...

The aim of this study was to investigate the possibility of producing chimeric bovine embryos by reaggregating blastomeres of disaggregated day 4 bovine embryos. Oocytes were obtained from a slaughterhouse. Selected oocytes were matured, fertilized and cultured in vitro. Fertilization day was taken as day 0. Blastomeres of day 4 embryos were disagg...

The aim of this study was to investigate the possibility of using synthetic serum substitute (SSS) instead of fetal calf serum (FCS) in maturation medium to stimulate in vitro maturation (IVM), fertilization (IVF) and subsequent development of bovine oocytes. Ovaries were obtained from a local slaughterhouse. Selected oocytes were matured in tissue...

The cryopreservation of pronuclear-stage embryos has a special importance in transgenic technology, cloning, and human-assisted reproductive technology. The objective of this study was to investigate the efficiency of a vitrification method modified in our lab for pronuclear-stage embryos. In experiment I, groups of 10 pronuclear-stage mouse embryo...

So far, most calves have been cloned from live adult cows or fresh fetal samples. There are few reports on using cells from a dead mammal for nuclear transfer (NT). This study was conducted to investigate whether different kind of viable cells could be obtained from tissues stored in cold for different duration and whether these cells could be used...

In vitro culture systems are required for many biotechnological and assisted reproductive technologies. In order to perfect the conditions, the effect of genetic background was evaluated in the in vitro development of embryos from CD-1 and CB6F1 mice in potassium simplex optimized medium supplemented with amino acids (KSOMAA). Presumptive zygotes w...

The objective of this study was to compare the developmental ability of embryos in 4 different media, CR 1aa, modified CR2, BCEM-g and TCM-199. Bovine oocytes were matured and then fertilized in vitro. A total of 915 oocytes were used for fertilization, 681 (74%) of which cleaved. The 2-cell embryos were divided into 4 groups, and cultured in 1 of...

This study consisted of comparative histopathological examination of endometrium in repeat breeder as well as fertile cows. In fertile and repeat breeder cows, hyperaemia, edema, and focal haemorrhages with the desquamated epithelial cells in gland lumens were observed. Subclinical endometritis was determined in 8 repeat breeder cows (53.33%). infl...

Cryopreservation of pronuclear-stage embryos would be useful for transgenic technology and genome preservation purposes. We compared a novel vitrification technique (solid surface vitrification, SSV) with another vitrification method in straws for cryosurvival and to generate transgenic progeny from cryopreserved mouse zygotes following microinject...

In this study, the influences of cumulus cells during in vitro fertilization (IVF) and their subsequent effects on mouse embryo development in vitro were studied in inbred and hybrid strain mice. Embryos at the 2-cell stage obtained after in vitro fertilization were transferred to the oviduct of foster mothers to assess their implantation rate. Mou...

This experiment was designed to determine the effects of CZB medium on in vitro culture of murine embryos obtained from FVB/N, CD-1, and CB6F1 strains. Pronuclear stage embryos were recovered from superovulated and mated females 17 h post-hCG. Two-cell stage block, morula and blastocyst stages were used as the end point of the experiments. There is...