Rat Oocytes Fertilized in Modified Rat 1-Cell Embryo: RESULTS(2)

Optimal Concentration of NaCl in mR1ECM-BSA for Sperm Penetration (Experiment 3)

Table 5 shows the proportion of oocytes penetrated during coculture with spermatozoa in mR1ECM-BSA containing various concentrations (90-140 mM) of NaCl for 10 h. The incidence of oocytes penetrated was high, and no differences were noted (p > 0.05) among mR1ECM-BSA medium containing 100-130 mM NaCl (88.8 ± 4.1% to 93.1 ± 5.1%). Rates of total sperm and monospermic penetration in mR1ECM-BSA containing 100-130 mM NaCl were not different (p > 0.05) compared to those in mKRB (81.6 ± 3.8% and 24.0 ± 7.7%, respectively; Table 5). However, the incidence of sperm penetration was reduced (at least p < 0.05) in mR1ECM-BSA containing 90 and 140 mM NaCl (21.0 ± 5.1% and 58.8 ± 13.2%, respectively). ventolin 100 mcg

Developmental Ability of Embryos Fertilized in mR1ECM-BSA Containing a High NaCl Concentration (Experiment 4)

Early development of embryos fertilized in mR1ECM-BSA containing 100-130 mM NaCl or in mKRB is shown in Table 6. More than 80% of embryos fertilized in mR1ECM-BSA containing 100-130 mM NaCl developed to the morula stage in mR1ECM within 96 h after insemination. The incidences of embryos developing to the morula and blastocyst stages were higher (at least p < 0.05) when oocytes were fertilized in mR1ECM-BSA containing 110-130 mM NaCl (92.5 ± 4.5% to 95.7 ± 2.6% and 85.7 ± 7.8% to 95.6 ± 2.7%, respectively) as compared to mKRB (69.2 ± 7.3% and 62.3 ± 6.0%, respectively). A total of 66 morulae and 3 early blastocysts that were fertilized in mR1ECM-BSA containing 110 mM NaCl and developed in mR1ECM were transferred into 7 recipients. Four recipients failed to maintain their pregnancies and resumed cyclicity on Days 13, 14, 16, and 20, respectively. Upon examination for implantation sites, an average of 7.0 ± 0.6 scars were found. The remaining 3 recipients maintained the pregnancy to term and delivered a total of 5 offspring (1.7 ± 0.3 offspring per litter; 4 males and 1 female) with average weights of 6.2 ± 0.4 g.

TABLE 5. Sperm penetration of rat oocytes in mKRB or mR1ECM-BSA1 containing various concentrations of NaCl.

Fertilization media Oocytes
No. examineda % penetratedb % with male and female pronucleic % polyspermicc
mKRB 64 81.6 ± 3.8e 100 ± 0 24.0 ± 7.7
mR1ECM-BSA with
90 mM NaCl 64 21.0 ± 5.1d 83.4 ± 9.6 10.4 ± 6.3
100 mM NaCl 53 88.8 ± 4.1e 90.8 ± 1.2 9.2 ± 4.3
110 mM NaCl 53 91.5 ± 6.5e 100 ± 0 16.4 ± 4.2
120 mM NaCl 56 92.0 ± 3.4e 97.9 ± 2.1 7.2 ± 4.2
130 mM NaCl 56 93.1 ± 5.1e 98.3 ± 1.7 8.5 ± 6.4
140 mM NaCl 62 58.8 ± 13.2f 77.5 ± 11.9 2.8 ± 2.8

a Oocytes were examined 10 h after insemination. Experiments were replicated 4 times. b Percentage (mean ± SEM) of oocytes examined. c Percentage (mean ± SEM) of oocytes penetrated.
def Means within columns with different superscripts are different (at least p < 0.05).

TABLE 6.

Fertilizationmedia No. of %b of embryos developed to
zygotescultured8 2-cell c > 4-cell c > Morula c Blastocyst c
mKRB 53 97.9 ± 2.1 86.0 ± 6.2d 69.2 ± 7.3d 62.3 ± 6.0d
mR1ECM-BSA with
100 mM NaCl 41 100 ± 0 94.6 ± 5.4de 86.1 ± 2.7de 84.3 ± 4.4de
110 mM NaCl 48 100 ± 0 97.0 ± 1.8de 95.7 ± 2.6e 95.6 ± 2.7e
120 mM NaCl 48 100 ± 0 92.8 ± 3.2de 92.8 ± 3.2e 92.8 ± 3.2e
130 mM NaCl 44 100 ± 0 100 ± 0e 92.5 ± 4.5e 85.7 ± 7.8e

a Oocytes were examined 10 h after insemination and only zygotes were cultured; experiments were replicated 4 times. b Data are expressed as means ± SEM.
c Numbers in parentheses indicate the time of examination (hours after insemination). de Means within columns with different superscripts are different (at least p < 0.05).

Category: Sodium Chloride

Tags: Cell Embryo, Oocytes, Rat, Sodium Chloride

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