Can Probiotics Affect Reproductive Processes of Aquatic Animals? - Aquaculture Nutrition: Gut Health, Probiotics and Prebiotics - page 336

to a lesser extent during vitellogenesis (Giorgini et al. 2010). These alterations, due to prote-
olytic events, controlled by the activity of cathepsins, were in accordance with the significant
increase in gene expression and enzymatic activity of cathepsin L (Giorgini etal. 2010), which
codifies for the enzyme involved in the yolk degradation responsible for FAAs release.
Fourier transform infrared (FT-IR) microspectroscopy has been employed to evaluate
macromolecular changes occurring during follicle development (Carnevali et al. 2009;
Giorgini et al. 2010; Gioacchini et al. 2012); it is a powerful and well-established technique
to study the composition and the macromolecular chemistry of cells and tissues, providing
a biochemical fingerprint of the samples under investigation and generating chemical
cartograms giving a semi-quantitative evaluation of the distribution of biocomponents
(Lasch et al. 2002). The identification and correlation of spectral groups (clusters), directly
evidenced on the images, can also be achieved by means of multivariate procedures (Tosi
et al. 2007; Walsh et al. 2009). Few reports have utilized spectroscopic studies on fish oocyte

IV

IIIb

IIIa

I-II

4000 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800

Wavenumber/cm − 1

Fig. 12.4 Representative FT-IR spectra in the range 4000-900 cm -1 of I-II, IIIa, IIIb and IV class follicles
from zebrafish. All spectra were further scaled on amide I band. On going from I-II to IV, some conclusions
can be drawn: (i) the vibrational mode at 1737 cm -1 relative to phospholipids, found as a shoulder in I-II,
becomes evident in III and IV classes; (ii) a small broadening of amide I and II bands indicates changes in
protein composition and secondary structure; (iii) an increase in the lipidic chains length is evidenced by
the 1452/1392 cm -1 intensity band ratio; (iv) the intensity of the bands at 1157 cm -1 (relative to
carbohydrates) and at 1080 cm -1 increases. (Source: Carnevali et al . 2009. Reproduced with permission
of Elsevier.)