Professor Alexander Zawadzki of Lvov university – Gregor Mendel’s mentor and inspirer

It is generally agreed that Johann Gregor Mendel (1822–1884) is the undisputed father of genetics, the study of heredity that is fundamental to our understanding of all living things. However, as a geneticist and engineer, strongly influenced by my teachers in Lvov and Gdansk, in Copenhagen and in Cold Spring Harbor (NY), I have always wondered how it was possible for Mendel to be such an independent thinker while not having a mentor who could have guided his creative and analytical thinking. Was there anybody in Mendel’s life who could have played this role? At the very least, did he get any opportunity to discuss his experimental designs with some colleague or to receive any help from a mentor or a friend in analyzing his results? The purpose in preparing this essay is to bring to light a long neglected story of how an «obscure Polish Professor from Lvov University», Alexander Zawadzki, played a critical role in helping an «obscure Austrian monk», Gregor Mendel, to create the discipline of genetics.Загальновизнано, що Іоганн Грегор Мендель є фундатором генетики – науки, яка вивчає спадковість, що є основою для розуміння всіх життєвих процесів. Однак як генетик, що перебував під впливом моїх вчителів у Львові і Гданьську, Копенгагені і Коулд Спрінг Харборі (Нью-Йорк), я завжди дивувався, як вдалося Менделю бути таким незалежним мислителем за відсутності у нього наставника, який міг би спрямувати його відкриття та аналітичний розум? Чи був хтось у житті Менделя, хто займав таке положення? У крайньому разі, чи була у ньго можливість обговорювати свої експерименти з кимось із колег та одержувати допомогу від керівника або друга в аналізі отриманих результатів? У представленій статті зроблено спробу висвітлити історичні факти, які довгий час перебували в тіні, як маловідомий польський професор із Львівського університету Александр Завадські допоміг непомітному австрійському ченцю Менделю започаткувати основи генетики.Общепризнано, что Иоганн Грегор Мендель является основателем генетики – науки, изучающей важнейшее для понимания всех жизненных процессов явление – наследственность.Однако как генетик, находящийся под влиянием моих учителей во Львове и Гданьске, Копенгагене и Коулд Спринг Харборе (Нью- Йорк), я всегда удивлялся, как удалось Менделю быть таким независимым мыслителем при отсутствии у него наставника, способного направить его открытия и аналитический ум? Был ли кто-нибудь в жизни Менделя, кто занимал такое положение? В крайнем случае, была ли у него возможность обсуждать свои эксперименты с кем-нибудь из коллег и получать помощь от руководителя или друга при анализе полученных результатов? В представленной статье сделана попытка осветить долгое время находившиеся в тени истории факты, как малоизвестный польский профессор Львовского университета Александр Завадски помог незаметному австрийском монаху Менделю создать основы генетики

Laying the foundations for a bio-economy

Biological technologies are becoming an important part of the economy. Biotechnology already contributes at least 1% of US GDP, with revenues growing as much as 20% annually. The introduction of composable biological parts will enable an engineering discipline similar to the ones that resulted in modern aviation and information technology. As the sophistication of biological engineering increases, it will provide new goods and services at lower costs and higher efficiencies. Broad access to foundational engineering technologies is seen by some as a threat to physical and economic security. However, regulation of access will serve to suppress the innovation required to produce new vaccines and other countermeasures as well as limiting general economic growth

A One Pot, One Step, Precision Cloning Method with High Throughput Capability

Current cloning technologies based on site-specific recombination are efficient, simple to use, and flexible, but have the drawback of leaving recombination site sequences in the final construct, adding an extra 8 to 13 amino acids to the expressed protein. We have devised a simple and rapid subcloning strategy to transfer any DNA fragment of interest from an entry clone into an expression vector, without this shortcoming. The strategy is based on the use of type IIs restriction enzymes, which cut outside of their recognition sequence. With proper design of the cleavage sites, two fragments cut by type IIs restriction enzymes can be ligated into a product lacking the original restriction site. Based on this property, a cloning strategy called ‘Golden Gate’ cloning was devised that allows to obtain in one tube and one step close to one hundred percent correct recombinant plasmids after just a 5 minute restriction-ligation. This method is therefore as efficient as currently used recombination-based cloning technologies but yields recombinant plasmids that do not contain unwanted sequences in the final construct, thus providing precision for this fundamental process of genetic manipulation

Glycosylases and AP-cleaving enzymes as a general tool for probe-directed cleavage of ssDNA targets

The current arsenal of molecular tools for site-directed cleavage of single-stranded DNA (ssDNA) is limited. Here, we describe a method for targeted DNA cleavage that requires only the presence of an A nucleotide at the target position. The procedure involves hybridization of a complementary oligonucleotide probe to the target sequence. The probe is designed to create a deliberate G:A mismatch at the desired position of cleavage. The DNA repair enzyme MutY glycosylase recognizes the mismatch structure and selectively removes the mispaired A from the duplex to create an abasic site in the target strand. Addition of an AP-endonuclease, such as Endonuclease IV, subsequently cleaves the backbone dividing the DNA strand into two fragments. With an appropriate choice of an AP-cleaving enzyme, the 3′- and 5′-ends of the cleaved DNA are suitable to take part in subsequent enzymatic reactions such as priming for polymerization or joining by DNA ligation. We define suitable standard reaction conditions for glycosylase/AP-cleaving enzyme (G/AP) cleavage, and demonstrate the use of the method in an improved scheme for in situ detection using target-primed rolling-circle amplification of padlock probes

A Differential Drug Screen for Compounds That Select Against Antibiotic Resistance

Antibiotics increase the frequency of resistant bacteria by providing them a competitive advantage over sensitive strains. Here, we develop a versatile assay for differential chemical inhibition of competing microbial strains, and use it to identify compounds that preferentially inhibit tetracycline-resistant relative to sensitive bacteria, thus “inverting” selection for resistance. Our assay distinguishes compounds selecting directly against specific resistance mechanisms and compounds whose selection against resistance is based on their physiological interaction with tetracycline and is more general with respect to resistance mechanism. A pilot screen indicates that both types of selection-inverting compounds are secreted by soil microbes, suggesting that nature has evolved a repertoire of chemicals that counteracts antibiotic resistance. Finally, we show that our assay can more generally permit simple, direct screening for drugs based on their differential activity against different strains or targets

Analytic philosophy for biomedical research: the imperative of applying yesterday's timeless messages to today's impasses

The mantra that "the best way to predict the future is to invent it" (attributed to the computer scientist Alan Kay) exemplifies some of the expectations from the technical and innovative sides of biomedical research at present. However, for technical advancements to make real impacts both on patient health and genuine scientific understanding, quite a number of lingering challenges facing the entire spectrum from protein biology all the way to randomized controlled trials should start to be overcome. The proposal in this chapter is that philosophy is essential in this process. By reviewing select examples from the history of science and philosophy, disciplines which were indistinguishable until the mid-nineteenth century, I argue that progress toward the many impasses in biomedicine can be achieved by emphasizing theoretical work (in the true sense of the word 'theory') as a vital foundation for experimental biology. Furthermore, a philosophical biology program that could provide a framework for theoretical investigations is outlined