E Sánchez, C Mardomingo, J Fernández
male, semen, short tail, sperm tail, spermatozoa, stump tail
E Sánchez, C Mardomingo, J Fernández. Stunted tail sperm defect: An Ultrastructural Study Of An Atypical Case. The Internet Journal of Urology. 2006 Volume 5 Number 1.
Objective: Atypical case of infertility associated with severe tail sperm abnormalities.
Methods: Familiar history, physical examination, semen analysis including scanning electron microscopy
Clinical Case: A 29-year-old man with four years of primary infertility. He had no history of significant illness and in his family was no cilia respiratory pathology nor male infertility. Physical examination of the patient showed no pathological findings. The analyses of four semen samples showed: sperm count 67-83 106/ml, and 0% motility. The morphological analysis showed mainly tail disturbances: absence of flagellum: 14-16%; short tail spermatozoa: 45-64%; coiled tails: 12-17%; and an abnormal proportion of spermatids and spermatocytes. Normal spermatozoa were found in a 11-16%. Endocrine profile was found within the normal range. Testicular biopsy revealed impaired spermatogenesis. Scanning electron microscopy revealed sperm heads with intact nuclei and acrosomal regions. To our surprise, the 12% of the stunted tails evaluated had biflagellate arrangement while the other ones had uniflagellate tail.
Conclusion: To our knowledge, this is the first human sperm with coexisting uniflagellate and biflagellate stunted tails.
Many cases of male infertility are associated with severe tail sperm abnormalities. The first reports of a syndrome characterized by stunted tails and sperm immobility was reported in rabbits1 and in bulls2. Electron microscopy demonstrated that the tail defect results in a blocked formation of the flagellum generating the absence of axonema and accessory fibres3.. This syndrome was known like
A 29-year-old man was presented in our reproduction department in order to be investigated of a four year primary infertility. He had no history of significant illness and neither the patient, nor anyone else in his family, had cilia respiratory diseases. His parents were not consanguineous and he had six bothers and three sisters with children. Physical examination of the patient showed no pathological findings.
Serum and sample analysis
Two serum samples were analyzed for follicle stimulating hormone (FSH), luteinizing hormone (LH), and testosterone (T) and were assayed by routine radioimmunoassay.
Four semen samples were collected by masturbation after 3 days of sexual abstinence and were analyzed within 1h of collection. PH, sperm counts, motility, live forms, morphology were appraised with standardized methods (World Health Organization recommended procedure 1999). Sperm morphology was assessed after Papanicolau staining on 100 spermatozoa according to the classification of World Health Organization.
A biopsy was performed on both testes, and samples were fixed in Bouin´s solution, embedded in paraffin, and sections stained with haematoxylin-eosin.
Electron microscopy procedure
The semen sample was diluted (1:3) with Ham´s F10 medium and spermatozoa were separated by centrifugation. The pellets were fixed for 2-4 h with 3% glutaraldehyde and postfixed for 2h in 1,3% osmium tetroxide. The spermatozoa were fixed in suspension with buffer washes between and after fixation steps. Sperm cells were subsequently sedimented on poly-L-lysine coated glass slide fragments and were dehydrated in a graded series of ethanol followed by absolute acetone, dried in Balzers CDP 030 (Balzers Union Ltd, Balzers, Liechtenstein) critical point dying apparatus using CO2 as transmission fluid, coated with gold-palladium in a Balzers Union CDP 040, and observed in a scanning electron microscope.
The analyses of four semen samples showed the following results: sperm count 278 106/ml (>20x106/ml), 35 % (>50%) alive forms and 0% (>50%) motility. No abnormality was found in biochemical parameters in seminal plasma. The morphological analysis revealed mainly tail disturbances: Absence of flagellum: 14-16%; short tail spermatozoa: 45-64% (Fig 1); coiled tails: 12-17%; and an abnormal proportion of spermatids and spermatocytes. Normal spermatozoa were found in 11-16% (> 30%).
Endocrine profile was found within the normal range FSH: 6.4 (2-8 mUI/ml), LH: 7.2 (2-12 mUI/ml), T: 28 (10-35 nmol/L).
Testicular biopsy revealed impaired spermatogenesis. It was also found reduced length tail spermatozoa in the seminiferous tubules lumen with a high percentage of degenerative spermatocytes and spermatids.
Scanning electron microscopy confirmed the abnormalities observed with optic microscopy (Fig. 2), and revealed sperm heads with intact nuclei and acrosomal regions. Surprisingly, around the 10% of the stunted tails which had been evaluated had biflagellate (Fig. 3) arrangement while the other ones had uniflagellate tail.
The semen analysed showed some, but not all the morphological defects described by Baccetti 4,5 for the ‘stump tail syndrome'. The spermatozoa showed a complete immobility and most of them had a reduced tail. However, it was found that the number of spermatozoa was not reduced and that the total sperm population was not affected by the extremely reduced length of the tails. Besides, in contrast to the ‘stump tail syndrome' which is characterised by the presence of only uniflagellate spermatozoa, our sample revealed the coexistence of uniflagellate and biflagellate stunted tails. Due to this observation, the morphological defect observed cannot been exactly classified either as ‘tail stump syndrome' or as ‘short tail syndrome' according to Baccetti's criteria4,5. To our knowledge, this is the first human sperm in which uniflagellate and biflagellate stunted tails coexist.
Our case confirms the testicular dysfunction of spermiogenesis as the origin of these kind of tail abnormalities. However the true origin of this defect remains unknown. Sperm and cilia disturbances are often reported to be associated and genetically determined; in fact, familial cases have been described in brothers8. Conversely, our patient had no familial history, neither others cilia disturbance, nor mail infertility. Therefore, this observation would suggest the possibility of an acquired defect or mosaics of genes that determine ciliary and flagelar axonemes.
This is an atypical case stunted tail sperm which has not been previously described and more cases will be necessary to describe properly these syndromes and to elucidate their origin.
Ernesto Sánchez Sánchez Avda. Juan de Mata Carriazo 6, 4º C 41018 Sevilla (Spain) firstname.lastname@example.org +34-609566292