## 4 Discussion  
Lindane, a pesticide commonly used on forage crops, is a known reproductive toxicant. It alters the endocrine system, altering estrogen-progesterone balance and affecting reproductive health [52; 53]. It has shown reproductive toxicity in both males and females across species, even at low doses (0.25 mg/kg/day, or 1/1000 th of its LD\({}_{50}\)) [54; 55; 56; 54]. Its lipophilicity allows it to bioaccumulate in biological fluids like follicular fluid, maternal  
\begin{table}
\begin{tabular}{c c c c c} \hline  & **Control** & **Lindane 1 \(\upmu\)M** & **Lindane 10 \(\upmu\)M** & **Lindane 100 \(\upmu\)M** \\ \hline \(\mathbf{N}^{\circ}\) **of mitochondria/50 \(\upmu\)m\({}^{2}\)** & 20.6 \(\pm\) 5.1 \({}^{\mathrm{a}}\) & 19.8 \(\pm\) 3.7 \({}^{\mathrm{a,c}}\) & 17 \(\pm\) 5.6 \({}^{\mathrm{a,c,d}}\) & 8.2 \(\pm\) 2.4 \({}^{\mathrm{b}}\) \\ \hline \(\mathbf{N}^{\circ}\) **of large SER vesicles/50 \(\upmu\)m\({}^{2}\)** & 5.6 \(\pm\) 1.7 \({}^{\mathrm{a}}\) & 6.8 \(\pm\) 3.2 \({}^{\mathrm{a}}\) & 7 \(\pm\) 1.6 \({}^{\mathrm{a}}\) & 9.8 \(\pm\) 2.4 \({}^{\mathrm{a}}\) \\ \hline \(\mathbf{N}^{\circ}\) **of MVBs and dense lamellar bodies/50 \(\upmu\)m\({}^{2}\)** & 3.6 \(\pm\) 0.5 \({}^{\mathrm{a}}\) & 4.4 \(\pm\) 0.9 \({}^{\mathrm{a,b}}\) & 6 \(\pm\) 1 \({}^{\mathrm{b}}\) & 9.2 \(\pm\) 1.3 \({}^{\mathrm{c}}\) \\ \hline \(\mathbf{N}^{\circ}\) **of CGs/10 \(\upmu\)m** & 2.6 \(\pm\) 1.1 \({}^{\mathrm{a}}\) & 2 \(\pm\) 1.6 \({}^{\mathrm{a}}\) & 1.6 \(\pm\) 1.5 \({}^{\mathrm{a}}\) & 1 \(\pm\) 0.7 \({}^{\mathrm{a}}\) \\ \hline \(\mathbf{N}^{\circ}\) **of microvilli/10 \(\upmu\)m** & 13 \(\pm\) 2.7 \({}^{\mathrm{a}}\) & 11.4 \(\pm\) 2.8 \({}^{\mathrm{a,b}}\) & 8.2\(\pm\) 1.5 \({}^{\mathrm{b}}\) & 8.6 \(\pm\) 1.1 \({}^{\mathrm{b}}\) \\ \hline \end{tabular}
\end{table}
Table 2: Morphometric comparison of organelle distribution in controls and in Lindane-exposed (1–100 \(\upmu\)M) MII-stage mouse oocytes. Values expressed as mean \(\pm\) SD. Differences in values considered significant if \(p\) < 0.05. Morphometry performed using one-way ANOVA with [PERSON]’s HSD post hoc analysis. Different superscripts indicate statistical significance (\(p\) < 0.05).  
and cord blood [22; 57; 58], and breast milk, increasing women's exposure risk [59; 60; 61]. Even with brief preincubation, Lindane impaired the growth of isolated primordial germ cells in culture, potentially due to apoptotic cell death, as indicated by increased caspase-3 activity and reduced AKT kinase phosphorylation [44]. An additional in vitro study showed that Lindane concentrations between 10 and 100 uM interrupted the formation of the first meiotic spindle and polar body extrusion in mice oocytes [62].  
Our work examined the impact of increasing concentrations of Lindane on the ultrastructure of mouse oocytes in an in vitro model. To the best of our knowledge, no prior studies have explored the effects of this compound on the ultrastructure of mammalian oocytes. At a concentration of 1 uM, Lindane caused minor morphological changes in mouse oocyte ultrastructure, including a slight decrease in mitochondria and CGs within the ooplasm, along with irregular microvilli. These early adverse effects became more evident at 10 uM, with notable reductions in organelle numerical density (particularly mitochondria), SER dilation, altered CG distribution, and changes in microvilli structure and quantity. At the highest concentration tested (100 uM), pronounced ooplasmic alterations were observed, including a significant reduction in mitochondria and CGs, pronounced microvilli thinning, cytoplasmic vacuolization, and SER dilation. The presence of autophagic vesicles and numerous secondary lysosomes indicates a potential cellular stress response. These findings demonstrate dose-related variations in ooplasmic organelle composition and morphology, suggesting impaired oocyte maturation or viability, consistent with previous studies [50; 63; 64].